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BLUEPRINT READING 



INSTRUCTION PAPER 



FREPABED BY 



HOWARD P. FAIRFIELD 

ASSISTANT PROFESSOR OF MACHINE CONSTRUCTION, 

■WORCESTER POLYTECHNIC INSTITUTE; 

AMERICAN SOCIETY OF MECHANICAL ENGINEERS 



AMERICAN SCHOOL OF CORRESPONDENCE 
CHICAGO » ILLINOIS 



K'^$ 



COPYRIGHT, 1920, BY 

AMERICAN SCHOOL OF CORRESPONDENCE 



COPYRIGHTED IN GREAT BRITAIN 
ALL RIGHTS RESERVED 



m 24 i9' 



©Cf.A565680 



BLUEPRINT READING 



INTRODUCTION 

Definition of Blueprint. A blueprint as used by engineers and 
by workmen in the various industries is a reproduction of what is 
known as a icorldiig drawing. A working drawing, as made by the 
draftsman, shows by means of lines what the piece, machine, or 
construction is, gives the necessary working dimensions and what- 
ever other data the workman needs to know in order to build the 
piece or the structure; in other words, it is the drawing by whicli 
the workman does his work and to which he looks for his informa- 
tion when building the structure or machining the part. However, 
it is essential that the working drawing itself be preserved for 
reference in the drafting room, and therefore a blueprint is made 
from the working drawing and this is what the workman uses at 
his machine or in the field. The lines, numerals, and letters on 
the original working drawing are black on a white background but 
these appear on the blueprint as white lines on a blue background; 
hence the name blueprint. 

Process of Making Blueprints. Blueprints are contact prints; 
that is, the blueprint paper and the working drawing are in con- 
tact with each other while exposed to the light. Blueprint paper 
is a strong rather tough white paper coated with a solution wliich 
is sensitive to sunlight and turns blue when exposed to sunlight 
and then washed in clean water. Those firms which use large 
numbers of blueprints often coat their own paper. Most firms, 
however, buy it in the open market already coated with the 
prepared sensitive solution. In making a blueprint, the working 
drawing is laid face do>Mi on a sheet of clear glass and the blue- 
print paper, cut to a size slightly larger than that of the drawing, 
is laid on the drau-ing with the colored, or sensitive, side next to 
the drav\ing and by means of a clamping frame is brought and 
held firmly in close contact with the drawing. The holding frame 
is then tipped and held in a position to allow the sim or other 
strong light to shine squarely through the glass. The light thus 



2 BLUEPRINT READING 

passes through those parts of the drawing on which there is no ink 
and effects a chemical change in the Hght-sensitive blue coating. 
The light does not shine, or pass, through the inked lines of the 
drawing, the lettering, or the numerals. After a short exposure 
to a strong light the clamps are removed and the blueprint paper 
is taken out of the frame and thoroughly washed in clean water. 
The parts upon which the strong light shone turn a rich blue 
color; those parts which came under the inked lines were not 
affected by the light rays and wash up a clean sharp white. 

Importance of Blueprints. The blueprint from a properly 
made working drawing should contain all the information needed 
by the workman in his work and he should never ask for informa- 
tion until he is positive that it is not on his blueprmt. It is well 
also for him to understand that his blueprint is an exact reproduc- 
tion of a drawing on file in the drafting room and that, if he implic- 
itly follows instructions and dimensions as given in his blueprint, he 
is protected in any argument which occurs over his work; in other 
words, if his work checks up with the blueprint he has worked 
from, any errors found in results are squarely up to the draftsman. 

What Blueprints Should Show. A blueprint is in a sense a 
picture of the piece, machine, or structure which is to be made or 
built. This picture is made up of view^; for example, front view, 
top view, end view, etc. (See "Mechanical Drawing," Part III, 
pages 73-79.) These views are made up of lines which would 
show clearly to the eye if the part, machine, or structure were 
viewed from the several positions noted; for example, a front view 
consists of those lines which would be clearly seen if the observer 
were viewing the part or machine from the front. The blueprint 
should also contain all the essential dimensions and indicate clearly 
from what surfaces they are to be taken In most cases, this is 
done by using a distinct arrowhead with the point resting against 
the line which represents the surface or the outline from which the 
measurement starts or from such a working line extended; that is, 
the line wjiich represents a surface edge is lengthened to make it 
convenient for placing the arrowhead. Another arrowhead is 
placed against the line representing the surface where the measure- 
ment stops, and the two arrowheads are connected by a line called 
a dimension line and the given dimension is placed either in this 



BLUEPRINT READING 



Z'ACROSS FLATS 




LINK STUD 
TWO -STEEL 

Fig. 1. Detail Drawing of Link Stud 



line or directly over it. Fig. 1 shows this. The blueprint will 
probably also contain lettered directions; some surfaces are to be 
ground, and the word "grind" may be lettered on those surfaces, 
others are to be polished, and 
on those the word "polish" may 
be placed. 

Reading Dlueprints. To be 
able to read a blueprint is as 
essential to a workman's success 
as to be able to read printed mat- 
ter. To read blueprints readily, 
he must know some of the prin- 
ciples of making drawings. These are explained to a considerable 
length and with close attention to detail in "Mechanical Drawing," 
Parts I, II, and III, and these books should be read most care- 
fully. This is somewhat equivalent to learning the alphabet in 
learning to read printed text. The workman should first under- 
stand that a blueprint is a record of instructions given him to 
read. Second, he should realize that the language used by the 
draftsman in making his drawing is largely a language of lines and 
that, unless he knows how to read lines, the instructions recorded 
on the blueprint are essentially in a foreign language. (Read care- 
fully and memorize page 41, "Mechanical Drawing," Part II.) 
To read a blueprint, the first thing is to study the several views 
until one has a good mental picture of what he is to construct. 
As the blueprint is a flat surface, it is necessary for the workman 
to use his imagination to make the lines and views lift up from 
the paper. WTien a clear-cut mental picture has been formed, the 
dimensions should be studied until understood. Next all the let- 
tered tex-t should be read and considered. Carelessness in any 
one of these three respects is not to be excused. 

GENERAL DIRECTIONS FOR READING BLUEPRINTS 

Method of Obtaining Views. As already noted in the "Intro- 
duction," a blueprint represents the information which the drafts- 
man is seeking to convey to the workman. It becomes necessary 
then for the workman to think somewhat as the draftsman thinks. 
Plate I, page 14, consists of three separate outlines, or diagrams. 



4 BLUEPRINT READING 

These diagrams are known as views and are obtained by project- 
ing the outKnes of the piece point by point onto an assumed plane. 
(Read carefully the matter under "View" and "Projection" in 
"Mechanical Drawing," Part III, page 73, and study Fig. 95.) 
In the case in hand, the paper on which the drawing is made is 
the plane, and as the blueprint is an exact reproduction, line for 
line and point for point of the original, it also can be said to be 
the projecting plane. As an aid in understanding what the drafts- 
man did when he made these mews and why they are placed on 
the paper as they are, let the reader imagine that with a sheet of 
paper he has made a box having all the corners and all the sides 
square with each other. Assume that the paper box is transparent 
as glass is transparent and that a piece of work might be hung 
inside the box centered with the sides and corners. Let us now in 
imagination hang various objects one at a time in this paper box 
centered squarely with its transparent sides through which they 
may readily be viewed. (Carefully study Fig. 102, "Mechanical 
Drawing," Part III, page 79.) If the first object selected is a per- 
fect cube, for example, an ordinary playing dice, then, viewing this 
from every side of the box, it is at once evident that all the views 
are the same in outline. If the outline dice is drawn, with a pencil, 
on each side of the box, as seen through that side, we will have six 
outlines all of the same size and shape. If an ordinary playing 
domino is substituted for the dice, the views when looking into the 
top and the bottom of the box will be alike in outline. Those 
seen when looking into the right and the left ends will also be 
alike, as will the views seen when looking through the back and the 
front sides of the box. If the pencil is used as before, six outlines 
are shown, but instead of their being each like the other, there are 
three pairs of views, each pair distinctly different from the others. 
If these penciled views are labeled top, bottom, front, back, right 
end, and left end, and the paper box is cut along its corners and 
the paper then tacked flat on a board, we have a drawing of the 
piece giving six views labeled top, bottom, etc. 

Instead of doing all this box work, the draftsman first trains 
his hands as shown in "Mechanical Drawing," Part I, pages 22-29, 
to use in a neat and skillful manner the various tools shown and 
described in pages 1-17. He also trains his hands to produce and 



BLUEPRINT READING 5 

his mind to remember the various outUnes shown in "Mechanical 
Drawing," Part II, pages 41-54. In addition, he must learn to 
imagine what he is going to make a drawing of, or, as it is termed, 
see the thing in space, which means form a reasonably complete 
mind picture of the piece he is to draw. In "iMechanical Draw- 
ing," Part III, pages 80-86, it is shown by what methods the 
draftsman avoids having to use a box with transparent sides when 
making a drawing; by using the tools shown in Part I, pages 1-17, 
in a certain conventional manner, he gets all the views he wishes 
on a sheet of paper tacked flat on a board. 

Number of Views Needed. It will be recalled that in view- 
ing the domino centered in the box, while we had six separate 
views, certain views duplicated and three views were sufficient to 
show clearly the outline of the piece. When drawn, some machine 
parts need several different views; others need only a single view. 
In Plate I the draftsman considered that he could get all the infor- 
mation the job needed on three views, namely, a front view a 
top view, and an end view. 

Interrelation of Views. In reading Plate I and other blue- 
prints, it will be observed that the top view and the front view 
center, line for line and point for point, on the same vertical center 
line, also that the front view and the end view center, line for line 
and point for point, on the same horizontal center line. Plate I, 
"Mechanical Drawing," Part I, page 26, shows a series of horizon- 
tal lines and a series of vertical lines, and it is explained in Part 
III, pages 73-86, how the vertical and horizontal reference lines 
work out in the drafting room. In some of the plates, it has been 
found necessary to readjust the different views to accommodate them 
to the small size plate, in violation of the rules of third angle projec- 
tion. The student should make allowance for these discrepancies. 

Meaning of Projection. To understand thoroughly what the 
term "projection" means, it is well to study the action of light as 
we view an object. Take as an example a man walking along the 
street. Our view of that man is made possible by the fact that 
light is reflected from his body into our eyes. This is true of all 
objects which we view with our eyes and we say that we see the 
man or the object. In other words, the light which is reflected, 
or thrown back, from the man or from the object into our eyes 



6 BLUEPRINT READING 

gives us a view of the man or the object. If the man or the object 
faces toward us, we get a front view, if away from us, a rear view. 
While the object itself is not a source of light, it is so treated in 
viewing it and the light is said to be projected from the object viewed. 
When a view drawing is made, it is often known as a projection. 

Projection of House. In "Mechanical Drawing," Part III, 
page 118, Fig. 160, is shown an isometric projection of the ordinary 
house. As an example of ordinary projection, suppose we select 
such a house and view it from its several sides, at a distance of 
not less than 100 feet from the several sides. Taking the front 
end first, the viewer will note that it appears as a flat wall having 
a rectangular outline with its top line in the shape of an inverted 
V. A side view gives a bottom line where the house rests on the 
foundation, two vertical, or upright, lines at each end of the side, 
a horizontal, or level, line to show the eaves, and a second hori- 
zontal line above this to represent the ridgepole. If these two 
views have been penciled out on a sheet of paper to some exact 
size, they will show what the outline of the house is. We can also 
show on these views the several doors, windows, etc., as we see 
them when viewing the front end and when viewing one side of 
the house, and if the rear end and the opposite side have the same 
doors, windows, etc., in exactly the same positions, the workman 
would be able from these two views to construct walls which 
would be as desired. If, however, the rear end had the doors or 
the windows placed differently from those on the front end or if 
they were not of the same size even though placed in the same 
manner, the workman would need a rear view to show him this 
fact. The same thing would hold true in respect to the sides of 
the house. Also, if the roof itself were broken up by windows, a 
top view showing their size and layout would be necessary for the 
workman. For convenience in making and reading the drawing, 
the several views are universally arranged for shop use exactly 
opposite the surfaces which they represent, as noted in the use of 
the box with transparent sides. 

Lines. Working Lines. A study of the views in the several 
blueprints in this book shows at once that each view is made up 
of straight lines and curved lines. The straight lines, or right 
lines (as they are often termed by draftsmen), are used to repre- 



BLUEPRINT READING 7 

sent the edges of plane surfaces. How such Hnes are drawn and 
the tools used for drawing them are shown in "Mechanical Draw- 
ing," Part I, pages 22-25. In the example just used, two upright 
straight lines a certain distance apart would be used to show the 
corners of the house. A circle line may show the edges of a 
cylinder or a hole in any surface, for example, a bolt hole or, in a 
house, a circular window. By using a combination of straight 
lines and part of a circle, the rounded end of a straight-sided 
bolt, for example, can be shown. Where the edges are neither 
straight lines nor parts of a circle, they are drawn with a special 
tool having an irregularly curved edge, which can be fitted to the 
desired line shape. (See Figs. 32 and 33, "Mechanical Drawing," 
Part I, pages 16 and 17.) A view, then, may consist entirely of 
straight lines, entirely of curved lines or of circles, or of a com- 
bination of all these. It must in any case be clearly noted that 
any working fine, straight or curved, is used to show where a sur- 
face on the work changes its direction, in other words, to show the 
edge of a surface. If the object viewed is a solid piece, for example, 
a bolt, all the working lines in the several views are solid and con- 
tinuous straight or curved lines. If the work has holes through it 
or has hollow places hidden inside it, the hnes which show the 
hidden edges are drawn as dots and the line is termed a dotted 
hne. (See Fig. 110, "Mechanical Drawing," Part III, page 84.) 
In studying a blueprint then, it will be understood that the dotted 
lines in a view represent surfaces and edges which are hidden from 
the viewer's sight when the object is viewed from the side shown. 
In the case of the bolt. Fig. 1, a view of the head end would 
show the body of the bolt as a dotted circle. In a blueprint of 
the house, the wall timbers, partitions, etc., which are not seen 
from the outside, would be shown as dotted lines. 

Dimension Lines. While the house outlines as they now stand 
give a general idea of how its exterior would look, they do not 
show its size or the sizes of the several doors, windows, trim, etc. 
To give this information, use is made of dimension lines drawn 
between points on the lines which make up the several views. 
To indicate the place where the measurement is to start and the 
point where it must stop, each end of a dimension line has a neat 
arrowhead, the point of which just touches the line at which the 



8 BLUEPRINT RFADING 

measurement starts or stops. Somewhere in the length of a 
dimension Hne are placed the numerals which give the exact 
measurement of the work as indicated by the arrow points. 
Dimension lines usually show on the blueprint much thinner than 
the lines which make up the views. This fact and the fact that at 
their ends are prominently placed neat arrowheads render it easy 
to avoid confusing them with the working lines of the blueprint. 

In case a dimension line cannot readily be placed on the view, 
the working lines may be lengthened, or extended, a short distance 
from the view and the dimension line can then be drawn between 
the extended lines with the points of the arrowheads resting exactly 
against the extended lines. The end of an extension line, as it is 
called, should never quite touch the working line which it extends. 

Section Lines. In addition to the working lines and the 
dimension lines on the blueprint views, the workman will, in some 
cases, find a series of parallel lines drawn closely together at an 
angle to the working lines of the view. These are known as section 
lines and are used by the draftsman to tell the workman that 
the part of the view covered by such lines is as if the work had 
been cut through and a portion removed. (Plate I, Fig. 3, 
"Mechanical Drawing,'' Part I, page 26, shows an example of 
section lines.) Sections open up the interior of an object or a com- 
bination of working parts, for example, the headstock of a lathe, 
and give a clear view of the inside. To use a homely illustration, 
the draftsman seeks the same effect as the grocer does when he 
cuts a melon in halves for the customer's inspection. A view so 
drawn is said to be sectioned; hence the term section lines. In the 
case of the lathe headstock, some of its parts may be of cast iron, 
some of bronze, some of steel, etc. To show which parts are of 
cast iron, of steel, or of bronze, the draftsman makes use of 
various arrangements of section lines, each arrangement showing 
a different material. In Plate III, "Mechanical Drawing," Part I, 
page 35, are shown and named the common arrangements of lines 
to show sections of different materials, viz, metals, wood, brick, con- 
crete, etc. The workman should study those common to his work. 

Drawing Sheet Sizes. In "Mechanical Drawing," Part I, 
page 2, is given a list of sizes of drawing sheets. While different 
shops may use different sizes for their blueprints, as a rule each 



BLUEPRINT READING 9 

shop has some regular system of sizes. A common system for 
machine shops makes the largest regular sheet 24"X36" and lists 
it size A. Such a sheet will fold and cut to give two B sheets 
18"X24". Continuing the folding and cutting gives a C size 
12"X1S"; a D size 9"X12"; and an E size 6"X9". A machine 
shop blueprint is usually trimmed to one of these sizes. 

Methods of Showing Large Work. Reducing Scale of Draidng. 
Several methods are used to make it possible to show a view of 
large work on a small sheet of paper. The view is often made a 
reduced size, which is usually spoken of as making it to a reduced 
scale. The term "scale" in such a case means that the length of 
the working lines in the blueprint views has a definite proportion 
to that of the actual lines of the work itself; for example, if the 
circles which represented the rim of a 24-inch pulley were drawn 
in a view as 12-inch circles, the view would be one-half size, or 
to one-half scale. If the circles were made 6 inches in diameter, 
the view would be to one-quarter scale. While in these cases the 
dimension lines would be, respectively, 12 inches or 6 inches in 
length from arrow point to arrow point, the dimension figures 
would read the exact size, 24 inches. For the reason that a blue- 
print view on a reduced scale does not give the average workman 
a good size picture of the work, it is customary to have the \dews 
show the work to exact, or full, size whenever it is practicable to 
do so. Such a view is known as a full-size view, or a full-scale 
view. The common machine shop vieiv scales are one-eighth, one- 
quarter, one-half, three-quarters, and full size. Another way of 
expressing view scales is in inches to the foot; for example, a one-half 
scale is 6 inches to 1 foot and a full scale is 12 inches to 1 foot. 

Shoiving Parts of Work. Another way of getting a view of a 
comparatively large piece of work into a small space on a blue- 
print is to show only a part of the work in the view. In the case 
of the pulley just mentioned, if the blueprint view showed one- 
quarter or one-half of the entire pulley, the average workman 
would be able to get all the directions necessary from the view to 
complete the work. 

Breaking the Piece. Yet another way by which the space 
utilized to represent a piece of work in blueprint views can be les- 
sened is what is known as breaking the piece. To illustrate, use is 



10 BLUEPRINT READING 

made of the front view of a long bolt or shaft of relatively small 
diameter. If such a piece were shown full scale, its working 
length lines might reach the entire length of the blueprint or even 
farther. If the body of the bolt or shaft is of uniform size and 
shape, it is suflScient to show a portion of the body near the head 
and a portion near the threaded, or opposite, end, and the portions 
shown may be brought close up to each other and thus little space 
used for the view. When analyzing the several blueprints repro- 
duced in the following pages, the ways in which space is utilized 
in representing the parts of the work will be noted. 

Shade Lines. It must be admitted that the average blue- 
print view of a piece of work is a rather flat and dead thing and 
that some imagination on the part of the workman is needed to 
give it life and to make it lift up from the paper and really have 
form and substance. Fortunately for the machine shop workman 
who is just learning to read blueprints, much of his work comes to 
him roughly in the form in which he is to finish it. This is espe- 
cially so when he is finishing ordinary castings. There are several 
methods used at times to give the blueprint views more "life". One 
much used method is to make certain of the working lines of 
increased thickness to represent a shaded portion. These heavier 
working lines are known as shade lines and aid somewhat in mak- 
ing the view stand, or lift, up from the paper. Such shade lines 
are used to a lesser extent now than formerly, as the workman is 
supposed to use his imagination when reading blueprint views. 

Line Shading. The term shade lines should never be confused 
with the term liTie shading which refers to a decidedly different use 
of lines. Line shading as commonly used consists of a series of 
lines placed on the view within its working lines and arranged in 
such a manner as to give a picture effect to the view. In "Mechan- 
ical Drawing," Part III, pages 126 and 127, are shown a variety 
of objects which have been line shaded. Comparison of these 
illustrations with Figs. 78, 81, and 84, "Mechanical Drawing," 
Part II, pages 49 and 50, clearly shows what line shading does to 
liven up a view. As is the case with shade lines, line shading is 
used less in machine shop- drawings than it formerly was. 

Finish Lines. Another line used in blueprint views is some- 
times termed a finish line. Such a line is usually broken up into 



BLUEPRINT READING 



11 



dashes and dots and is then known as a dashed line. It is placed 
on the view close to a working line to indicate that the surface 
represented by the working line is to be finished. Dashed lines 
are now little used for this purpose because of the chance of their 
being confused with dotted lines used to represent hidden surfaces 
and edges, and other methods of indicating finished surfaces are 
popular. Brown & Sharpe practice is to use a red pencil to draw 
a full red line on the blueprint views close beside all working lines 
which represent finished surfaces. A common method of indicat- 
ing finish is to place a letter / across all working lines which 
represent finished surfaces. 

Symbols Used. There are a number of words which often 
appear on blueprint views, each conveying certain information, and 
the workman must be familiar with the more commonly used ones 
to read his blueprint readily. The word "ream" near a hole 
shown in the view means that the hole is to be finished by ream- 
ing it; the word "tap", if so placed, indicates that the hole is to 
be tapped. The terms which the workman is most Ukely to find 
on his blueprint views are ream, tap, grind, polish, scrape, frost, 
taper, crown, and drill. He will also often note the letters F.A.O. 
near certain views; when so found, they denote that the piece of 
work is to be finished all over and the letter / is left oft' the work- 
ing lines. It is also common machine shop practice to place on 
the blueprint the name of the piece of work, the number wanted, 
and the material to be used, all neatly lettered. The several 
materials used in the construction of machinery are usually indi- 
cated by their initials, for example, M.S. for machinery steel. To 
read blueprints easily and accurately, the workman should learn 
the symbols used, the more common of which are given and 
defined in the following tabulation: 



F.A.O finished all over 

f finished surface 

RAD radius 

DIAM diameter 

R.H right hand 

L.H left hand 

P.R piston rod 

P. Tap pipe tap 

CTRS centers 



C.I cast iron 

S.C steel casting 

Bz bronze 

C.R.S cold rolled steel 

T.S tool steel 

O.H.S.'. open-hearth steel 

W.I wrought iron 

M.S machinery steel 



y 



12 BLUEPRINT READING 

Special notes neatly lettered are often placed on the blueprint and 
these notes should always be read carefully. In "Mechanical 
Drawing," Part I, pages 17-21, and Part III, pages 128-134, are 
shown examples of lettering. Each and every dimension hne 
should have in clear distinct figures, either on the line or in a 
break in the line, the exact dimension which the dimension line 
represents. Dimension figures should be clear, distinct, and easily 
found and read. (Study Plate I, Fig. 4, "Mechanical Drawing," 
Part I, page 26.) Certain working variations in dimensions are 
allowable in all work. These are termed tolerances and should be 
given on the blueprint. They are usually preceded by the sign =t 
and are placed near or follow the given dimension. If the toler- 
ances are not to be found, the workman must learn what the 
practice of the shop is in regard to this point. 

Conventions Used. Certain conventions, as they are called, 
are often to be found on blueprints. Take screw threads as an 
example; they are seldom shown on a blueprint as actual threads 
but are indicated by an arrangment of parallel lines across the sur- 
face meant to be threaded, Fig. 1, page 3, and a note is usually 
lettered on or near the threaded surface giving the number of 
threads per inch and the form of the threads. Gear teeth are 
seldom shown on a blueprint; a lettered note is used instead to 
state the number of teeth in the gear and whether they are 
involute, cycloidal, or otherwise. 

Intersections and Irregular Surfaces. While, in most cases, 
the workman can get the needed information from a sufficient 
number of views of the ordinary method of projection, this is not 
always true where two surfaces meet at an angle, especially if 
they meet or intersect at other than a right angle. As an example 
of such a case, take the spout of an ordinary tin coffee pot where 
it joins the body of the pot. In uniting the two, it is necessary to 
know just what the shape of the hole should be and its size; also, 
in making up the pot body and the spout body, each of which is 
usually tapered, it is necessary to know the exact shapes and sizes 
to which the sheet tin must be cut. All sheet-metal work is full 
of such problems, as well as work in leather, for example, shoe 
tops, bags, etc. To obtain the desired forms of the holes and the 
body of a sheet-metal object, it is in effect cut open and flattened 



BLUEPRINT READING 13 

out as if it were a sheet of paper. The methods by which such 
problems are solved are very clearly shown in "^Mechanical Draw- 
ing," Part III, under the headings "Intersections," pages 98-106, 
and ."Development of Surfaces," pages 106-113. WTiile the work- 
man's blueprint should show the already developed surface, or pat- 
tern, he will better understand his job if he knows how such a 
pattern is made. 

Single Picture Views. The practice in some shops is to fur- 
nish the workman with a small blueprint which has a single view 
of the piece he is to work on. These sketches can be made by 
the use of the regular draftsman's tools or, given sufficient artist's 
skill, may be made free hand. The excellent examples of such 
sketches given in Plates XXIX, XXX, and XXXI were, in the 
original, entirely free hand. Where one view is sufficient to show an 
object in its true shape, it must show the object tipped and turned 
into such a position as to give a picture view. The sketch artist 
views the object from a variety of angles, finally decides which view 
best shows the piece, and makes that the blueprint view for the 
workman. In "Mechanical Drawing," Part III, pages 113-125, 
the methods used to obtain these single picture views are described 
and illustrated. 

Importance of Careful Study. The careful reader of the pre- 
ceding text must now be impressed with the need of knowing 
things. The way to know a thing is to study it, just as a child 
studies his book when learning to read. The child first learns the 
simpler words, how they look, what letters of the alphabet are 
used in spelling them, how the words are pronounced, etc. Any- 
one who is willing to study this text and "Mechanical Drawing," 
Parts I, II, and III can learn how to read ordinary blueprints 
readily. To assist the reader of this text in doing this, a variety 
of simple blueprints have been selected for analysis. Although 
they by no means cover all classes of work, nevertheless, they have 
been selected from a large number as being the more typical 
of their kind. Carefully study each blueprint as well as the text, 
for, in the first place, you will become acquainted with good 
practice as carried out by several well-known firms and, in the 
second place, you will, by this thorough analysis, train yourself to 
see in any blueprint everything that was intended to be brought out. 



14 BLUEPRINT READING 

ANALYSIS OF TYPICAL BLUEPRINTS 

PLATE I 

SADDLE NUT 

It is evident that Plate I shows three views of a saddle nut. 
Before starting to read the views, the workman should read 
the lettered data at the top of the blueprint. From this he gets 
the name of the piece he is to make, "saddle nut," the number 
required, "one, on a single machine," the name of the machine to 
which the piece belongs, "5-foot boring mill," and the piece num- 
ber, "14049." He next reads the lettered data at the lower edge 
of the blueprint and learns what material he has to work on, in 
this case, bronze. If this plan has been followed out, the workman 
now knows that he is to make a certain number of bronze saddle 
nuts, each of which is a part of a 5-foot boring mill. 

The several views are a front view, a right end view, and a 
bottom view. The front view shows the piece as it would look when 
set on its flat base on the bench, with its long side toward the 
viewer. The right end view shows the piece as it would appear 
if set on the bench as before, but so placed that the right end 
would face the viewer as he stood at the bench. The remaining 
view shows the bottom, or base, of the piece as it would appear 
if the workman picked the piece up from its first position on the 
bench, held it above his head, and looked up at its bottom side. 
As both ends of the saddle nut are alike, no left end view is nec- 
essary; and as nothing is to be done to its upper, or top, surface 
or to its rear side, neither a top nor a rear view is necessary. 

The dotted lines through the front and the bottom views 
show that there is a hole through the length of the work and the 
right end view shows that the hole is circular in shape. As the 
dotted lines through the front and the bottom are double lines 
exactly centered with the center lines of these two views and as 
the right end view shows a full-line circle and a dotted-line circle, 
something more than these lines are needed to tell us just what 
this hole is. Between the front view and the right end view are 
certain notes nicely lettered. They state that the hole has a left- 
hand square thread, four threads to the inch through its length, 



: OP MACHINE PIECE NO. 

'J BORING MILL 1404-9 



APPROVED BY 



TT.NO. SIZE LENGTH PIECE NO. 
14049 




NAME OF PIECE 

SADDLE NUT R.H. HEAD 



AMI REQ. NAME OF MACHINE PIECE NO. 

/ 5^'" BORING MILL 14-049 



-t^z: 







— 


A 




r' 1' 1 V 

— Hi 

1 i w \\ 





^.zd^,..::^ 



-i' DRILL FOR #5 TAPER PIN 
DRILL 70 SUIT 



^H" DRILL I" TAP 
DRILL TO SUIT 



[approved by 



/40/9 6ROUPN0.TPACE0BY0ATE CHECKED _„_„.,^,.,.,.^, p, .^.p p^. MATERIAL USE RATI N^^ LENGTH PIECE NO. 

14011 RSillha^ 4.17.17. ^ THECINCINNATI PLANER CO. 5^(j^^^ J4049 



BLUEPRINT READING 15 

make everything clear as to what the hole is, and explain the name 
"nut" given to the piece in the title. 

Near the base of the front and the right end views are cer- 
tain other dotted lines which, of course, represent hidden surfaces 
or holes. When we look at the bottom view, it is easily seen that 
these are round holes. By reading the notes placed at the right 
of this view and by following the arrows, we learn that two of 
these holes are to be made to fit a No. 5 taper pin and that the 
two larger ones ^.re to be drilled and tapped for a f-inch screw. 
This view also shows that there is a screw hole and a pin hole in 
each end of tlie piece and that the screw and the pin holes are 
placed in corners diagonally across from each other. It can also 
be seen by reference to the several views that the screw holes and 
the pin holes are placed on the same center lines. If the workman 
is used to general machine construction, he will know that the 
screw holes are for the bolts which are to hold the saddle nut to 
the saddle and that the pin holes are for the taper pins which 
locate and hold the nut to an exact position. The bottom view 
shows by dimension lines placed just above the view tliat the 
holes are to be placed 3 inches from each other along the length 
of the piece and f inch in from the edges of the base. The end 
view shows by dimension lines placed just below the view that 
along the width of the piece the holes are 2 inches apart and 
f inch in from the sides. The workman should understand that 
when the dimension lines are shown in this manner, the ccntcr-to- 
center distance is the more important one. In this case, the 2-inch 
and the 3-inch dimensions are of more importance that the f-inch 
dimensions, these latter being probably given to inform the work- 
man that the holes must be symmetrical with tlie base of the nut. 

Attention is called to the placing of the dimension lines 
between or at the side of the views and to the fact that the arrow 
points touch extension lines drawn to nearly touch the surface 
lines. Dimension lines placed between the front view and the 
bottom view show that the saddle nut is 4| inches long over all 
and that the over-all length of the base is 4^ inches. Dimen- 
sion lines placed just below the right end view show that the 
base of the nut is 3^- inches wide over all. A dimension line 
placed just above the end view shows that the rounded part of the 



16 BLUEPRINT READING 

nut is 3 inches. While reading the over-all dimensions, for example, 
the 4|-inch, the 3|-inch, and the 3-inch dimensions, the workman 
should at the same time see whether or not his castings measure 
up fairly close to these dimensions with finish allowances. 

Attention is called to the fact that all the dimensions are given 
either in whole numbers or in whole numbers and common frac- 
tions, with the exception of the dimension for the bore of the hole, 
which has added to it the decimal 0.003. This would indicate that 
the various dimensions given, with this one exception, are not of 
exceptional importance, or that the workman will be furnished 
with a special gage, or that the work will be jigged. 

In this blueprint, it will be noted that the surfaces to be 
finished are indicated by the letter / placed on the working surface 
lines. As thus indicated, the base of the nut, the right-hand end, 
and the hole through the nut are to be finished. 

PLATE II 
BACK CLUTCH PINION 

The lettered data at the upper edge of Plate II informs us 
that the piece is a back clutch pinion for a 5-foot boring mill and 
that one is required on each boring mill. Lettered data also tells 
us that the material is machinery steel and that the rough stock is 
5| inches in diameter and 4| inches long. 

The views given are a front view and a left end view. As 
the work is round with a plain squared-up right end, two views, 
as shown, are sufficient for the workman to understand what the 
piece is as well as to get all his dimensions. As an aid in read- 
ing the blueprint, the front view shows the piece as if it had 
been cut in halves through its length. The parts of this view 
which show where the cutting is made in solid stock are cross- 
lined at an angle of 45 degrees with the working lines. Referring 
to "Mechanical Drawing," Part I, page 35, it is seen that the 
cross-section lines are arranged to show that, as previously stated, 
the material is machinery steel. 

As the first machine operation on this piece of work is that of 
getting a hole chucked through its axis, or length, the workman 
will naturally read his drawing for the size of the hole. At the 
right hand of the front view we find a dimension line with the 



NAME or PIECE 

BACK CLUTCH PINION 



AMI REQ. NAME OF MACHINE PIECE NO. 

/ S^^ BORING MILL I4I4I 




CUT 5 TEETH ^•'CLEARANCE 



i"TAP. ^" DRILL ^ #0122 



APPROVED BY 



GROUPNQTf?ACEDBY DATE CHECKED 

14-004- cA-i 5.9.17 9^ 



THE CINCINNATI PLANER CO. 



IIAL USE PATT.no. SIZE LENGTH PIECE NQ 
5i" 4t 14141 



BLUEPRINT READING 17 

arrow points touching the diameter lines of the hole extended, as 
explained in "General Directions for Reading Blueprints." The 
figures placed in the dimension line inform us that the hole is to 
be made 2f inches, and as the left end view shows a central circle, 
the hole is a round one. The word "ream" placed on the dimen- 
sion line to the right of the dimension figures shows that the hole 
is to be drilled sufficiently small to permit it being reamed to its 
exact figured size. This dimension, as well as all the other dimen- 
sions, in the original blueprint, read two times the actual distance 
between the arrow points as shown on the views. The views in 
the original blueprint are then one-half the size of the actual 
piece of work and are drawn to one-half scale, in other words, G 
inches on a view represents 12 inches on the actual work. 

The next two machine operations on this piece are to square 
the ends to the over-all length and to turn and finish it to the 
exact diameter. By following the end extension lines upward, we 
find at their upper ends a single dimension line having arrowheads 
\\'ith their points touching the extension lines. By reading the 
numeral placed in the line, it is found that the over-all length is 
4 inches. Thus far this blueprint is very easily read. 

Before starting work on the diameter, the views and the let- 
tered text must be more carefully read. The name of the piece, 
"back clutch pinion," and a study of the views show it to be a 
gear with a clutch on its left-hand end. 

Following out the extension lines to the left and to the right 
of the front view, which represent the several working diameters, 
we learn that the surface where the gear teeth of the pinion are to 
be cut is 5 inches in diameter. By following the upward extension 
lines, it is seen that the right-hand ends of the teeth do not start 
at the exact end of the stock but \ inch to the left of this. The 
extension lines also show by proper dimension lines that the faces 
of the teeth are to be 2\ inches long. In this same view, the 
upward extension lines and dimension lines show that the remain- 
ing length of the piece from the left-hand end of the pinion teeth 
is 1^ inches. Following the diameter extension lines to the left, 
we learn that the diameter of this part of the work is 4j inches. 

A further study of the Irft end of the front view and of the Irft 
end view will show that the inner diameters of the clutch teeth are 



18 BLUEPRINT READING 

counterbored out to 3| inches with a depth of | inch. The right- 
hand end of the work is turned into the form of a hub having, 
according to the dimension hne near that end, a small diameter 
of 3| inches but curving up into a fillet. Both views show that 
there is a tapped hole through one side of the piece, and the let- 
tered data placed just below the front view tells us that the hole 
is to be drilled with a ^-inch drill and tapped with a f-inch tap. 
Both views show the clutch teeth. 

In the left end of the front view, extension lines carried 
upward have dimension arrowheads and numerals which show that 
the clutch teeth are to be cut | inch deep. The left end view 
shows the general form of the clutch teeth. A lettered note just 
below this view states that there are to be five teeth and that the 
spaces between the teeth are to be | inch wider than the teeth 
themselves. This indicates that the teeth in the mating part of 
the clutch and the teeth in the piece shown in this blueprint will, 
when in mesh, clear each other by a distance of ^ inch. A let- 
tered note placed just below the front view informs us that the 
gear teeth are twenty-three in number and that a five-pitch cutter 
is to be used in cutting them. 

No finish / marks are placed on the various working lines 
in either view, but a lettered note F.A.O. tells us that the piece is 
to be finished all over. Two dotted lines on the front view indi- 
cate that there are hidden surfaces — in this case, the right-hand 
and the left-hand ends of the gear teeth of the pinion. If this 
text has been carefully studied, the reader will readily understand 
that Plate II really represents two pieces of work made solid 
in one piece of stock, namely, a toothed clutch and a pinion gear. 

PLATE III 

DOWN-FEED WORM WHEEL 

In reading Plates I and II, it will have been noted that in 
Plate I three views were needed to show the workman all he 
needed, while in Plate II two views were sufiicient. In Plate III 
a single view shows all that is needed to build this piece of work 
completely. The data on the upper edge of the blueprint states 
that the piece represented is a down-feed worm wheel for the right- 
hand head of a 5-foot boring mill and that one is required. The 



NAME OF PIECE 



AMI REQ. NAME Or MACHINE 




DOWN FEED WORM WHEEL ff^ol ONE 3^^ BORING Ml LI 114061 



■■sH 



'-f'Xf^'KEYWAf 




W»l 






52T icP. 
LH. THREAD 



APPROVED BY 



GROUP NQ TRACED BY DATE CHECKED T-McriMriMKiA-ri d. AMtrorn MATERIAL USE PATT NO. SIZE LENGTH PIECE NO 

I40II mmims^ 4-19-17 ^ THECINCINNATI PLANER CO. ^^^^^^ ^^^^^ 



BLUEPRINT READING 19 

data on the lower edge tells us that the material is bronze, which 
is also indicated by the arrangement of lines in the cross-sectioning 
of the view. 

A worm wheel is a toothed gear with the gear teeth cut at an 
angle with the sides of its rim. This angle is such as will make its 
teeth readily mesh, or fit, into the screw threads of the worm 
which is used to drive it. While the driving worm is not shown 
on this blueprint, a dimension line at the right of the view, with 
one of its arrow points touching the center line of the worm wheel 
and the other touching another center line drawn near the lower 
edge of the blueprint, shows that the center-to-center distance of 
the worm and the worm wheel is 3f inches. Lettered data near 
the lower center lines states that the worm wheel is to have thirty- 
two teeth of |-inch circular pitch and that the worm will have a 
left-hand thread, two threads to the inch. 

In reading Plate III, let us first study the view itself. We 
will see that it is the view seen by a viewer facing the central axis 
of the piece and is, therefore, a front view. Lines drawn on the 
view at an angle with the working fines show that it is a sectional 
view, the piece having been cut along the center of its length pre- 
cisely as a watermelon is sliced along the center of its length. 
Since the view is shown in this way, it is somewhat easier to read. 
The fact that one view only is given to work from indicates : (a) that 
if the work were viewed from its ends, the views would show on 
the blueprint as circles; and (b) that the ends of the work are 
plain and squared up — hub and rim. The lettered data, as already 
noted, states that the piece is a toothed gear wheel. Altogether, 
the piece is shown to consist of a hub, a rim, and a connecting web. 

Following the upward extension lines and the dimension fines 
which they carry, it is seen that the over-all length of the piece 
is 2f inches and that the rim width is !§ inches. The upward 
extension lines and their dimension lines also show that the worm 
wheel hub extends, or projects, to the left of the rim a distance 
of f inch. Dimension lines on the body of the view show: (a) that 
the wheel hub is lf| inches long; (b) that the rim overhangs 
the right end of the hub ^ inch; (c) that the right end of the 
hub projects | inch beyond the web; and (d) that the web is 
i inch thick. Following the extension fines to the left of the view, 



20 BLUEPRINT READING 

we learn that the hub is 3 inches in diameter and that the chucked 
hole in the hub must ream If inches. These extension lines also 
show that the over-all diameter of the toothed rim is 5| inches. 

The curved diameter on the rim, as shown, is known as the 
throat diameter, to distinguish it from the over-all diameter. 
Following the extension lines to the left of the view, it is seen that 
the throat diameter is 5.4114 inches. The dimension line placed just 
over the rim with its arrow point touching the throat curve is 
drawn from the point where the short center line crosses the 
center line of the wheel rim. This dimension line indicates that the 
workman should machine the curved part, or throat, of the rim 
with a cutting tool having its cutting end formed to an arc of a 
circle of 1.0443 inches radius. The remaining radius dimension 
line has its arrow point resting on the curved working line which 
represents the inner surface of the wheel rim. 

The teeth in worm wheel rims are invariably cut or machined 
by the use of a special tool known in shops as a hob, or a hobbing 
cutter. In using a hob to cut the gear teeth, the workman has to 
know to what depth the cutting teeth are to be sunk into the rim 
of the wheel. The sketch in the upper right-hand corner of Plate 
III indicates in outline the teeth, or threads, on the worm and on 
the hobbing cutter. This sketch shows: (a) the angle of the sides 
of the threads; (b) the center-to-center distance, | inch; (c) the 
total depth of the hob thread, 0.3433 inch; and (d) the narrowest 
width of the hob thread and the space, 0.155 inch. The short 
note at the right of the view tells us that a keyway is to be cut 
in the surface of the hub hole f inch wide and ^ inch deep. 

The / marks placed on the working lines of the view show that 
the sides and the outer surface of the rim and both ends and the 
hole through the hub are to be finished. 

PLATE IV 

INTERMEDIATE SHAFT CLUTCH 

The piece shown in Plate IV is very nearly the same as that 
shown in Plate III. The practice is, however, that of another firm 
and the piece is represented by three views : a front view, a right end 
view, and a left end view. Reading the lettered data shows the 
piece to be an intermediate shaft clutch. The cross-section front 



SECTION A-B 






15 TEETH- 10 PITCH 



_ //„ REAM 
16 LAP 



H' C'BORE g"DEEP 
BOTH ENDS 



INTERMEDIATE SHAFT CLUTCH 

I- CARPENTEQ *5-5l7 STEEL 
HEAT TO I475°F. QUENCH IN OIL AND 
DMW TO 550/ 5 60 °E TO SHOW 65/75 
SHORE 5CLER05COPE. 



mm^ AAU. DATE ^-/i?-/?' MACHINE 



TRACED A.flJ. 
CHECKED J.BA 
APPROVED 
ACCEPTED 



2-16-17 PART 
2-1(3- 17 



aWlaiaMililB 



JOB 2855 R.o. 

PART NUMBER 
TICKET 



5 


m 


I 








i \CYAN ADDtD 
C UMn." ADDtD 



± 


-fU 


^■^ 


/,'-» - 



-4- 



® 

/- C.g.S. CYAN 



IHTW I'll I Itil I 'I II I » !■ i ■■ 




VJnitL GUARD T-BOLT 
2- C.R.S. 



mcHmLsm-am!fiM(imD..mm job 2355 bo 

PART SW/£i. TABU STUD PART NUMBLR 63 

TICI\tT 



TRACtD CEC ~ 11-17-16 PART SMi'a TABU STUD PART NUMBLR 63 

Cnicm ADAMS " 11-22-16 I TICH^T 

-- -V. ;■ II-Z6-I6 TheTaft-Peirce Mf'g. Company. WooNsocKET.RI. USA 



DATC BY 



4-5ia\t.FL\ 



H-ri.H DATE 7-6-/7 MACHINE 

HM. ■ 7-6-17 PART 

AOAMS ■■ 7- 6-17 



JOB 2855 
PART NUMBER 
TICKET 



LE.T ALTEfiATIONS DATF BY 1 



A \ DtUMAlS ADDtD \ZXm\M. 
B ADDO) DIM. 4-ZJ-/7 (»• 



NOTE- TURN ii" BUT 
CUT THREAD l"-ll 



DIAMOND TOOL POST T-BOLT 
I- CSS- CYAN 



aK)55 FEED 
CONNECTING LINK 
I- CI. 




DRAWN DATt MACHINE 

TRACED EPL •■ 4-10-18 PART 

CHECKED ADAkIS • 4-/5-I8 

APPROVED HO^, " 4.-I5-I8 -r -r 

ACCEPTED " IHEIAFT 



JOB 2555 R.O. 
WRT NUMBER 
TICKET 



TheTaft-Peirce Mfg. Company. WooNSoc^ET.RI. U.S.A. 



DRAWN DATE MACHINE 5CMI- UNIVCIfSAL 

TRACED HADUV » 512-16 PART 0RINDIN6 MACniNt 

CHECKED ADAM5 •' J- i- 16 

APPROVED m,. . T.-,6 theTaft-Pe,«ceMf<iCom 



JOB 2655 R.a 
PART NUMBER -J45 
TICKET 



BLUEPRINT READING 21 

view shows that the material is steel, and a further reading of the 
lettered note tells us that the company knows this steel as Car- 
f)enter No. 5-317 steel. The left end view shows the general form 
of the clutch teeth. A line drawn across this view near a single 
tooth shows that a section has been sliced off at this point. The 
line is lettered A-B at its opposite ends to enable the workman to 
find the view of the part sliced off. 

Directly above the left end view is a small view named "sec- 
tion A-B". This shows a single clutch tooth viewed as if looked at 
from the inner, or small, end of the tooth. Extension lines pro- 
jecting upward from the working lines of the tooth show that the 
tooth sides incline 5 degrees from the vertical. No other view 
shown tells us this, and therefore it is necessary for the workman 
to have this small section. 

The right end view shows that the clutch teeth are slanted 
along their sides at an angle of 20 degrees, or, expressed another 
way, the sides of the clutch teeth make an angle of 20 degrees 
with each other. From a further study of this view, we learn that 
the inner surfaces of two adjacent teeth make an angle of 52 
degrees. The lettered note at the right and the arrowhead tell us 
that the inner ends of the clutch teeth are counterbored ff inch 
in diameter and | inch deep. Just above the front view at each 
end arrow points have the numerals 0.124-0.126. The decimal 
fraction for | inch is 0.125; the numerals 0.124-0.126 then show 
that the |-inch depth must be cut to a tolerance of not more than 
O.OOI inch above or below the figured depth, I inch. The right 
end view clearly shows that this shaft clutch has gear teeth in its 
outer surface, and data under the front view states that there are 
to be fifteen teeth, ten pitch. The only other note for the work- 
man's use is that giving the size of the keyway. 

PLATE V 
DETAILS OF FOUR MACHINE PIECES 
General Data. In the study of Plate V and of all succeeding 
plates, it will be assumed that the workman has thoroughly 
studied all that has gone before and understands what is meant by 
front, top, bottom, and end views, by sections, and by extension 
and dimension lines, and that he can find and read the dimensions. 



22 BLUEPRINT READING 

Plate V is made up of four blueprints of small details and 
■illustrates the way in which the Taft-Pierce Company send such 
into their shops. The number placed in the circle located in the 
upper right-hand corner of each small print is the part number of 
the piece and will be referred to in this text as the blueprint num- 
ber. It will be noted that blueprints Nos. 63, 440, and 113 are all 
blueprints of bolts. 

Swivel Table Stud. The piece shown in blueprint No. 63 is a 
swivel table stud for a semiuniversal grinding machine. A note 
placed just beneath the view states that the material is cold rolled 
steel, cyanide hardened. Only one view, a front view, is given, 
which indicates that the end views would show as circles. From 
this single view the workman can get all length dimensions and all 
diameter dimensions. Among the things to be noted in this blue- 
print are that the right end of the stud is to be threaded ten 
threads per inch and that some of the dimensions are given in 
pairs, for example, those of the body of the stud. This means 
that the length of the body and the diameter of the body, respec- 
tively, must lie within the given pair of figures for that dimension. 
Take the case of the body diameter; it must not be greater than 
0.999 inch nor smaller than 0.998 inch, a tolerance of one-half of 
one-thousandth inch above or below a central dimension. 

Wheel Guard T Bolt. Blueprint No. 440 is a wheel guard 
T bolt, and the note tells us that two are required and that the 
material is cold rolled steel. A front and a right end view are 
given. If a single front view of this piece were shown, the work- 
man would infer that the bolt head was a circle; the end view 
shows that the bolt head is square. A left end view instead of a 
right end view would indicate this equally well, but in that case 
the circles which represent the body of the bolt would be dotted 
circles instead of showing as they do in the right end view. There 
are no finish / marks in either view because the piece, as noted, is 
made from cold rolled steel bar stock, which has a finished sur- 
face, and when the bolt is turned to size, the outer surfaces of the 
head have the original finish of the bar. Moreover, to construct 
the rest of the bolt naturally finishes those parts. 

Diamond Tool Post T Bolt. Blueprint No. 113 is a diamond 
tool post T bolt, and the lettered note states that one is required 





i 


.!«. 


-^ 





§"I?EAM 



CENTER REST TOP 

I- CAST IRON 



mmniJennings DATE J--?4-/7 MACHINE 
TRACED " PART 

CHECKED J.B.A. « 4-2-// 



JOB 2355 R.Q 

PART NUMBLR 
TICKET 



APPROVED 
ACCEPTED 



The TAfT-PEiRCEMre. Company. WooNsocKET R.I. U.S.A. 



BLUEPRINT READING 23 

and that the material is cold rolled steel, cyanide treated. Two 
views of this piece are necessary. The views differ from those 
shown in blueprint No. 440, since the view showing the bolt head 
is a left end view. Placed in this way, the circles which represent 
the body part of the bolt show as dotted circles. Another inter- 
esting thing is that the body dimension of the bolt is given by the 
dimension figures as f inch, while a lettered note with an arrow- 
head tells us that the body of the bolt is turned to a diameter of 
It inch and that the threaded part is | inch in diameter and has 
eleven threads per inch. The end view shows that the bolt head 
inclines at an angle of 60 degrees with the base line. 

Cross=Feed Connecting Link. Blueprint No. 345 shows a 
front view and a top view of a cross-feed connecting link. One 
only is required and both the lettered note and the arrangement of 
cross-section lines inform us that the material is cast iron. Where 
the shape of the cross-section is simple, as shown, it is usual to 
place it directly on one of the views rather than make an additional 
view. The cross-sections of pulley arms, connecting rods, and 
links are generally shown by this method. The workman in read- 
ing this blueprint should note that the reamed holes have limiting 
dimensions given and also that the thickness of the hubs is held to 
a small tolerance. The finish / marks clearly show what surfaces 
are to be machined. 

PLATE \T 
CENTER REST TOP 

The lettered data states that Plate VI is a blueprint of a 
center rest top. One is required and the material is cast iron. A 
short study will show the machinist that many of the dimensions 
are given to or from horizontal or vertical center lines; also that 
some of the dimensions are plain distances, in which case the 
dimension line has an arrow point at each end, while others are 
from a center point and give the radius from that point of the 
working line which represents the surface. When a radius dimen- 
sion is given, it is usual to place the initial letter R. or the letters 
Rad. after the dimension figures. 

In the front view, the workman should especially note that 
the hole through the length of the upper part of the piece is to 



24 BLUEPRINT READING 

be drilled and reamed a part of the way and drilled and tapped 
eighteen threads per inch for the rest of its length. Another 
important item is that, while the radius of the hub is given as 
Y6 inch, the frame back of the hub is machined back to a radius 
of f inch. 

In the right end view, the things which the machinist should 
especially note are that one end of the lower hub is marked /, 
while the opposite end is marked "disc grind", indicating that the 
/ end is to be carefully finished to an accurate bearing, while it is 
not necessary to be so particular with the opposite end. The end 
view also shows that the hole in the hub is to be drilled and reamed. 
The hole just above the hub is to be drilled and tapped for a 
i^-inch screw, eighteen threads per inch. 

PLATE VII 
CENTER REST BASE 

A reader of this text who is familiar with machine work 
knows that a center rest is a fixture used in turning or grinding to 
give support and steadiness to long or slender work. Plate VIII 
gives a complete view of a center rest and indicates its use and, 
before taking up a study of Plate VII, it will be well to glance at 
Plate VIII. 

The lettered title of Plate VII states that it is the blueprint 
of the center rest base. One is required and it is made of cast 
iron. The piece of work shown is then the mate of that shown 
in Plate VI and some of its features and dimensions are the 
same. A complete front view and a complete right end view are 
given as well as a portion of a top view, which is placed directly 
above the left upper corner of the front view. 

The workmg lines of the bottom of the front view and the 
end view show that the base is provided with a squared projection 
used to locate the center rest on the bed of the machine. Aside 
from tWs, the machinist should notice the data which relates to 
finishing the small hub at the top of the end view and at the 
upper right corner of the front view. The term "spot face |" " 
indicates that the surface touched by the arrow point is to be 
finished, by using a counterbore | inch in diameter, to the limiting 
thickness given just above the end view. It should be noted that 



25 



irN^^ 



^>^^' 



^ 


^ 


s 




ll 


Ill 




fAC£ /| DIA. 



SPOT faces' 
TO ill * 




CENTER REST BASE 
1- CI. 





ORAWAJ 

TRACED 

CHECKED 

APPROVED 

ACCEPTED 


O.R.. 
ADAMS 

mad 


DATE 4.-Z4-/7 

- 4--27-I7 
., 4-27-17 


MACHINE 

TOOL 

PART 


JOB m5 RO 

TOOL NUMBER 
TICKET 


THE TAFT-PIERCE MFG. COMPANY. VTOONSOCKET. R.I. U.S. A 










CENTER RE5T ASSEMBLY 



DATE MACHINE 

" 4-Z4-n TOOL 

■I 4-27-n PART 

» 4-Z7-17 „,^,.„ 



JOB Z8i5 R 0. 

TOOL flUMBlB 
TICKET 



THE TAFT-PIERCEMFS COMPANY. WOOMSOCKET R.I.U.S.A 



—i. OIL OPOOVE 
—J/'^'WDtl^'DtlP 



.d:» 




I \ TAPEl^^^^70\l-FT. 



DO NOT PUT IN THIRD TAP I ^np qf TAPER 



dm >i>^ ,5,, 



^!3itrft?:^n^nrr 



ROUewm CUTTERS FOR WAYS 

PLU6 GAUGES FOR STRAIOHT BEARIN6 

PLUG GAU6E5 FOP WOPn SPINDLE HOLE 

SHELL REAMER FOR WOPK SPINDLE HOLE 

Jia FOR ELEV. SCR. NUT HOLE 

TEST BAR FOR 5CRAPIN6 

DRILLS SCREAMERS 

JI6 FOR DRILLING 

FORM TOOL FOR REAMER Vrnj^ 

0AU6E FOR WAYS 

FIXTURE FOR ROUGH MILLING 
FIXTURE FOR FINISH MILLING 



WORK SPINDU SLIDE 

.r-, PI3 



J_ CLAMPS 



SCALER SIZE 



NO. 13 AUTO. GEAR CUTT. M'CH. 
WORK SPINDLE SLIDE 



DATE OCT Z9 1915 e/f/'&mjf- EX. A.B.C. 
BROWN 8r SHARPE MFG. CO.. 



PROVIDENCE. R.I. 



BLUEPRINT READING 25 

certain of the holes are drilled and reamed while others are drilled 
and threaded -with a tap. The machinist should carefully observe 
on which of the working lines of the views the / mark is placed, 
lie should also note in Plate VII, as in Plate VI, that many of 
the dimensions are given to or from horizontal or vertical center 
lines and that all dimensions bear a certain relation to a common 
center, or axis, A. In reading the dimension figures, the machinist 
will find that several of them have a limiting error tolerance telling 
him that he must be especially accurate in those dimensions. 

PLATE VIII 
CENTER REST ASSEMBLY 
Plate VIII shows two views, and the lettered title placed just 
below the views states that the piece is a center rest assembly. 
The two views furnish a line picture of the completed center rest 
and show all its separate parts as they are wlien assembled or, as it 
is often termed, set up. It will be noted that each and every part 
is given a number. These numbers are known as the piece, or 
part, numbers. 

PLATE IX 

WORK SPINDLE SLIDE 

Compared with many of the blueprints shown, Plate IX, 
showing the work spindle slide, is difficult to read and it has been 
selected to illustrate a fairly complicated and irregularly shaped 
piece. As an aid in reading this blueprint, a short study should 
be made of the general form and shape of the piece as shown in 
outline in the front, right end, and top views. An examination of 
the views shows that the piece consists in general of two hubs, or 
cylinders, with holes through their length. The cylinders are 
placed with the smaller above the larger and arc connected by a 
short web running their entire length. When the reader clearly 
sees this and has the picture clearly in his mind, he can then 
study the various small hubs, bosses, and other pieces attached to 
the two long hubs and their connecting flange. 

In tracing the location and shape of the several parts, holes, 
etc., it should be kept clearly in mind that each part in the front 
view, if shown in the top or in the end view, will be squarely 
above or squarely to the right of its position in the front view. 



26 BLUEPRINT READING 

Another thing which aids the reader in getting a picture of the 
piece in mind is its name, "work spindle sHde." The note just 
over the name plate, "Scale Half Size," of course applies to the 
original blueprint only and not to the reproduction in this text. 

Several helps in the form of lettered notes are on this blue- 
print. As an example, attention is called to a note at one end 
of the front view which tells us that the dotted lines on which the 
arrow points touch represent oil grooves | inch wide and ^ inch 
deep. From a study of the upper part of the front view and 
of the end view we learn at which points the oil grooves start and 
also that they are drilled at an angle of 45 degrees to reach 
the surfaces of the slide bearings. 

Among the specially important things to be noted is that, 
while the hole through the length of the smaller of the two long 
hubs is a straight plain cylindrical hole, the hole through the 
larger is tapered at its right-hand end f inch to the foot for a 
distance of 5| inches. Attention is also called to the two slide 
bearings on the rear side of the work, one slide bearing having right- 
angle sides and the other a 60-degree side. Threads per inch on 
blueprints at the shops of the Brown & Sharpe Manufacturing 
Company are invariably given by Roman numerals. For example, 
as may be noted on the blueprint, a hole threaded fourteen threads 
per inch is marked XIV. Also, each surface which is to be 
finished is indicated by drawing a brilliant red line close beside the 
working line which represents the surface. On this plate and on 
Plates XII and XIII these lines are shown dotted and are drawn 
close to the finished surface lines. Lettered notes placed on this 
blueprint state what special tools should be got from the tool 
room before starting the work. 

PLATE X 
DRAWINQ=IN BOLT 

Plate X shows a drawing-in bolt, and the lettered note just 
below the name tells us that one is required, that the material is 
cold rolled steel, that it is a forging, that it is forged on a heading 
machine, and that it is to be casehardened as shown. The fact 
that the forging is done on a heading machine indicates that the 
head end only is upset to its rough shape. The letters C.H. 




€^ 


i;. 4" > 

—I A 




ilH^^IH 


■■H^Ml 


IS 


lE^Hi^ai 


e> 



cli. W??5 



=,!*; ^ CUT. 002 -.003 5. 
~^^^ ON PITCH DIAM. 



DRAWING IN BOLT 

I-C.R.5. A2Z7a A, B.C. FORGING. 
CASE HARDEN A5 SHOWN. 
FORGED ON HEWIN6 MACHINE. 



SYMBOL A 2278 A A= 25g 
U5ED ON C2 

SYMBOL A 2278 b' A- 29§' 



SYMBOL A 2273 C A' 
USED ON C5 



DRAWINQ IN BOLT 

DATE APRIL 25 1917. A.P.D. EX.fi.S.i 

BROWN & SMARPE. MFG. CO., 



A2278 



D£VtLOPM£NT OF CLUTCfi T££Tt1 
SPACLS .005 WIDER WAN T££Tfi 




RtC£55r,D££P 







J-j" OIL NOUS ■ 
DRILL IN POSITION AtTER 
TAKING FROM 5T0Cn 



/ GRIND 
^NO.4- TAPtR PIN 



knee: StlAFT CLUTCH 

M.S. 
FORMED TOOL #984-6 



3T0C/r:- 

2/q" DIAM. X 23" L0N6 



AZ, AA-i. b&m. B5. BB3. C2 

MNEL SHAFT CLUTCtI 
DATE DEC. 28 1916 Jl.Cr. EX. A.H.C. 
BROWN & SHARPE MFG. CO.. 



A2227 



., .--^;iiu.-iii-^»- 



mmmmmmmmi. 



BLUEPRINT READING 27 

placed just below the threaded end and just below the f-inch 
hexagon end show that the bolt is to be casehardened at these 
places, according to the lettered notes. One view only is given, 
which indicates that an end view would show circles unless other- 
wise specified. A note at the extreme left end of the view states 
that the end is made a f-inch hexagon. 

All length dimensions are easily read with one exception, that 
of the over-all length, which is represented b}^ the capital letter A. 
Notes lettered on the blueprint at the lower right-hand corner 
inform us that, when this bolt is made for and used on C2, A is 
25| inches in length, and when it is made for and used on C3, A 
is 29^ inches. While all the diameter dimensions are easily read, 
the machinist should surely note that several of them have let- 
tered notes giving additional information. For example, we read 
that the ^-inch diameter is to be ground 0.001 or 0.002 inch 

small, "Gr. < " „^ >S." In this blueprint, the letters Rad. are used 

instead of the capital letter R. to denote a radius. 

PLATE XI 

KNEE SHAFT CLUTCH 

The title plate at the lower right of Plate XI tells us that the 
piece of work shown is a knee shaft clutch. Further information 
given on the title plate indicates that this clutch is used on A3, 
AA3, BBH2, etc. A lettered note placed on the blueprint just 
below the two views states that the knee shaft clutch is to be 
made of machinery steel, that the rough stock is a piece measur- 
ing 2i^"X2^", and that a certain formed tool is used by the 
machinist. All the length and all the diameter dimensions are 
easily found and read, while a copious use of notes gives the 
machinist much special information. For example, a lettered note 
placed just below the front view tells us that a certain hole is 
drilled in position after the piece is taken from stock. This indi- 
cates that when finished by the machinist to be placed in stock, 
this hole is left oil" and that when the setting-up man gets the 
piece from the stockroom, he places it in position and then drills 
it in place. Before starting work on this piece, the machinist 
should read all notes. The front view is a complete section. 



28 BLUEPRINT READING 

In this blueprint, the information concerning the clutch teeth 
is contained in a small view placed somewhat above the front 
view and named a "development of clutch teeth." This view 
represents the outer surface of the clutch teeth rolled out on a 
flat surface, as explained in "Mechanical Drawing," Part III, 
page 107. The note tells us that the spaces between the teeth are 
0.005 inch wider than the teeth. The view also shows that the 
sides of the teeth slant to an angle of 5 degrees. The end view is 
sufficiently complete to show the form of the clutch teeth only, a 
lettered note placed just below the view giving the number of clutch 
teeth as eleven. As both views show that the piece of work is by 
construction finished all over inside and out, no finish needs to be 
indicated. 

PLATE XII 
BACK TOOL POST 

The title plate informs us that the piece shown in Plate XII 
is the back tool post and that there are a set of tool posts. A 
lettered note placed at the upper right tells us that the tool post 
material is M.I. and that it is to be casehardened to have a 
mottled surface. This plate, like Plate IX, lists up the special 
tool-room tools for the job. The views given are front, top, and 
end views supplemented by a small section view, placed just above 
the right end view, showing a section on line A-B. 

This small A-B section shows that the bottom of the large 
slot running through the tool post is at an angle of 5 degrees with 
the back surface of the slot. The working lines of this slot, as 
shown in the front and the end views, indicate that the top sur- 
face of the slot is parallel to the top surface of the tool post and 
that the lower, or bottom, surface of the slot makes an angle of 
20 degrees with a center line drawn parallel to the upper surface 
of the slot. Working lines, drawn as full lines in the front and 
the end' views but dotted in the top view, show a projecting 
feather on the under side of the tool post base. Clearly defined 
dimension lines and figures give the width, depth, and length of 
the piece. The machinist should note that the width is to be 
made standard 0.001 inch small; also that certain base surfaces 
are to be surface ground. 








TOOL POST fBACM) 

l-M.I.-C.H. MOTTLED -^ 



SECTION ON 
A-B 



JI05 rof? DJ?/Ll/N6 # //944 iC 11944-2 
FIXTURt roe MILLING WfOO£ 3L0T » 1194^ 6(//945-l 
FIXTURE FOR MILLING BOTTOM # 11959 
OANO OF Z CUTTERi FOR MILLING 5L0T »9n7-#9l78-#9m 
ANGULAR CUTTER5 # 11957 
CUTTERS #11^4? 

f# 11980 
5PECIAL VI5E FOR 20° \ # 11980 - I 
.# 11980 -4 



<.52^ ^Te^m 



""V 




5YMB0L F62-B 



SET OF TOOL POSTS 



TOOL POST (BACn) 

DATE APRIL 19 le 16 J. PR. EX.-S^ 



BROWN & SHARPE MFG. CO., 




WOOO LINER BErOQE CHUCKIN6 
BODY CBOR£ f^'DtlP ~x\ Z^'" QOmURBODE l^'DZtP 



H 4" i 



QRIND-^ 


Ms 


^ 

1 


■ "■"' ""^ ^"t 






iiisssisi 



furnish:- "• 

1- STY. 3 />■! B-4 CL.BOLT \t 3* 

2- STY. 20 A'-H-B=i CEN. A.BUSH. 

l-STY.ZTA-i B-l a. PLATE. . MADL 

I- STY. 56 A--^ 

1- STY. 56 A=i 
I ■ STY. 89 B=} #2- ADJ. WOPM FIXTURE I 

2- STY 90 k'\ 8=1 KPM 5.CL. BOLT FIXTURE / 
; • STY 90 h-l B--i CEN. ARM H£AD JI6 FOR i 
2-5TYI0IA=i B'ft ARM 5. CL BOLT TOOLS FOi 
2- STY.lOiA^ 8=1 D--II ARM CL BOLT JIOFORDRt 
ISTY.20lAi 8-i D'li CLAMP BOLT 

I - CENTRE A52 

I- CENTRE ADJUSTING WORM /1 53 

I -CENTRE ADJUSTING WORM BU51IIN6 AI93- COUNTFRBORE FOR SCREWS 

I ■ CENTRE ADJUSTING WORM HEAD AI94-DRILL FOR #2 TAPER PIN- C.H. 

I ■ ARM SUPPORT CLAMP BOLT (L0N6) AI33B-A 

I ■ ARM SUPPORT CLAMP BOLT (SHORT) A 1538-8 

;- CENTRE ARM HEAD CLAMPIN6 PLATE AZ55I 

I - CENTRE ARM BU5/IIN6 B52-A 

I - CENTRE CLAMP BOL T ^^ .-j—' 

;■ CLAMP PLATE SPRING WASHER ^1^°' ^xt_ 

/ - CENTRE aAMP NUT BUSNINO ^T^ SEE SKETCH fifl 

XIII 



SECTION A-B 



CZNTK ARM HEAD 
C.I. A 2513 

MADE ON M0ULDIN6 MACniNF 



FIXTURE FOB CHUCHING # 12247 

FIXTURE FOR FACIN6 HUBS §12248 

016 FOR DRILLIN6 # 12249 

TOOLS FOR DRILLING (SEE LIST) 

JIO FOR DRILLING AU RUSH SCR HOLES *I2250 



SCALE I SIZE 



'^%RAB.BORE 
IN POSITION 







JIG FOR DRILLING PIN HOLES # 12251 

JIO FOR DRILLING PIN HOLE TO LOCATF BUSHING 012252 

CUTTERS FOR MILLING ARM BRACE SEAT * 12253 012254 

ARBOR FOR SPLITTING # 12235 

GAUGE FOR TESTING CENTRE DISTANCE * 12255 



Al{, A2. AA2. Bli B2. fiS2. 5Y/. BY2. Bl. 
AAI. AAlj. BBI. BBll 

CENTRE ARM HEAD (COMPLETE ) 

DATE JUNE 18 1917 dK. tt. A.H.C. 

BROWN & SHARPE MFG. CO.. / 



PROVIDENCE. R.I. \ 



A23I3 



BLUEPRINT READING 29 

PLATE XIII 
CENTER ARM HEAD 

Plate XIII is in some respects similar to Plate IX. In read- 
ing this plate, the machinist should first strive to get a general 
picture of the piece well fixed in his mind. As an aid to this, he 
will first note that the work, a center arm head, consists of two 
principal hubs separated by a web or shank to give a center- 
to-center distance of 7j inches. The upper hub is simple, having 
as it does a plain hole through its length and a binder boss on its 
upper side to be drilled, tapped, and counterbored for a binder 
bolt. The lower hub, however, is well surrounded by projecting 
parts which, as they carry several holes and other finished sur- 
faces, decidedly present difficulties to the reader. He will do well 
to take up each hole as shown in the end view and study each as a 
single hole, getting its position located in each view. 

The larger hole, it will be noted, passes entirely through the 
main lower hub. The hole placed' slightly above this hole and to 
the right hand of the end view can," by studying the front view, 
be seen to pass entirely through its hub from end to end. The 
upper hole of the three shown to the left of the main lower hole 
will be found to be placed on a center line with the one just 
noted. A small cross-section view just above, lettered "section 
A-B," aids the reader in clearing up the details of this hole and 
the two similar lower holes; he should carefully note where the 
section line A-B is drawn on the end view. A study of the front 
view and of the section view shows that the upper of the three 
holes passes entirely through the casting from end to end. A 
study of the two lower holes in the end view shows that they 
break into each other. Their location in the front view and in 
the small section view indicates that, while the hole farthest to the 
left passes entirely through the casting, the other, which cuts into 
it, is only IJ inches deep. Extensions of the centers of these two 
holes show by dimension figures that their center-to-center dis- 
tance is ff inch, and a radius line just below the end view shows 
that the center of the outer hole is 2g-inch radius from the center 
of the hole in the main lower hub. 

Diagonally drawn dotted lines in the end view represent a 
hole coming in from the front of the casting at an angle of 22 



30 BLUEPRINT READING 

degrees 35 minutes. In the front view this hole and its boss show 
at the side as a series of full and dotted circles. A lettered note 
placed on the end view at the right of the vertical center line of 
the view states that an oil hole is to be drilled. Following care- 
fully the lines which represent the oil hole, the reader will find 
that it is to be drilled at an angle of 17| degrees with the center 
line of a similar j^-inch hole showing through the lower side of 
the main hub hole. Further examination of the end view draws 
attention to two small circles at the sides of one of the |-inch 
holes. A study of the small section view shows these circles to 
represent holes drilled, tapped, and counterbored for screws II 
having a f-inch filister head. A radius arc drawn from the hole 
beside which these screw holes are placed shows that their centers 
are placed at 3^-inch radius. Other screw holes, oil holes, and pin 
holes can easily be located by a study of the views. In reading a 
blueprint such as this, especial care must be used in locating all 
center lines, radius lines, extension lines, dimension lines, and lines 
showing angles. 

PLATE XIV 

BRASS GLOBE VALVE 

Plate XIV shows a l|-inch brass globe valve and the original 
blueprint is made to full-size scale. Two views only are given. 
The front view shows the valve sectioned as if cut down through 
and on the center line, thus clearly giving an inside view of the 
valve. The end view gives an outline of the valve and is in a sense 
a picture of the valve. The arrangement of the cross-section 
lines in the front view indicates that the sectioned metal parts of 
the valve are, with the exception of the cast-iron handwheel, brass 
throughout. By means of the outline view and the section, the 
draftsman has not only shown all the necessary dimensions of the 
valve as an assembly but has also shown those of each detail so 
well that the machinist can work it out. While it is not general 
practice in shops to have the workman work from assembly blue- 
prints, it may well be done when a shop is building a standard 
article. As there are no finish lines nor / marks, the workman 
would have to decide for himself what surfaces should be finished, 
if given this drawing to work from. 

The several parts of the valve as shown on the blueprint are 



aSi/ 




BOJ?£ 0UID£5 2 A' 



ZCKU. FULL SIZE \ li" BRA55 6L0BE VALVE 

DRAWN BY F.P.R.. THE 

TRACEDBY fl.X.S PRATT £^ CADY CO.' 
SvT^<: HARTFORD. COAI^. 




SIZE OF NQ OF TEETH 
MACH. AND PITCH 



A 33T SP. 



B 40T 8P 



\C\ 50 7. 8P\ 



u 631. ap 



i| 3/ T 7P 



J 39T 7P 



\C\ 48T. 7P 



\U\ 601. 7P. 



\\Z01 6 P 



, 6 Z&l 6 P 



\C\ All 6 P 



\D\ 5S1 6 P 



\A\ 291 5P 



. \B\ 35T 5R 



OUTSIDE WIDTH 
DIA. OF FACE 



8.8 5 7 



5.333 



6.666 



8.16 66 



10.000 







PART 
NO. 








16810 




13625 




15606 








16808 








16769 








10849 




12666 








/6767 








16898 








11448 





D\ 55 1 5P. \ 11.400 



N AMF '^'^^^'f^. ASSCMBL£D CONE 6CAR5 mAt 



U5LD0N 2-S-4-5- PA.l/A- Z-3-4-\^A. Z-(JH6cPH- 5PH 



I DRAWN 6Y G.W. I DATL F£6. PS. 09 MAV 25. 10. NttWAI 



cHtLcntDBY5.if. THE CINCINNATI MILLING MACHINE CO. amount^JpaRt 

APPROVED ET CINCINNATI. OHIO. ^^|||^NUM6 



15713 



BLUEPRINT READING 31 

the valve body, consisting of a globular shaped casting with 
threaded hexagon ends into which, on its upper side, is screwed 
the valve cover casting with a threaded bearing for the long 
spindle; and an upper part, consisting of a stuffing box for the wick 
packing. At the extreme upper end of the stuffing box are a 
small circular gland and a gland nut to force it along the valve 
spindle to compress the wick packing into the stuffing chamber. 
The valve spindle has on its top end a squared taper end to fit the 
cast-iron hand wheel and a threaded hexagon nut to hold the hand- 
wheel in place. Toward its lower end an enlarged part of the 
valve spindle is threaded with a rather coarse-pitch Acme thread 
to fit the threaded bearing in the valve cap. The extreme lower 
end of the valve spindle is enlarged and finished to carry the valve 
disc which seats itself on the valve body seat to close the flow 
through the valve body from end to end. The disc, or upper, 
seat moves up and down in narrow guides, as shown in the front 
section view, and a lettered note placed just below this view states 
that these guides are to be bored 2^r^ inches in diameter. The 
disc has in its lower, or seat, side a circular recess, lyf inches out- 
side diameter by 1^ inches inside diameter, for a fiber, leather, 
asbestos, or other seat ring. Two dotted lines about y6 i^^ch apart 
drawn diagonally across the inside of the valve body, as shown in 
the front view, represent a diaphragm rib. This is an interesting 
blueprint to read, as it is necessary to locate carefully all the 
extension lines to learn which icorklng lines they extend. Care 
must also be taken to determine which lines many of the arrow 
points exactly touch. 

PLATE XV 

ASSEMBLED CONE GEARS 

Plate XV illustrates a method of using an assembly drawing for 
shop purposes. The view shows a cone of four gears in section on 
a shaft. The arrangement of the cross-section lines indicates that 
the gears are made of machinery steel. As shown, the whole cone 
of gears is mounted on a steel sleeve which, in turn, runs on a 
composition sleeve. The whole combination is held in position on 
the shaft by steel collars having hexagon-head set screws. As is 
customary in such section views, the shaft is not shown sectioned. 



32 BLUEPRINT READING 

Its ends, however, are shown as if broken off and the arrangement 
of the section Hnes at the break indicates that the shaft is of steel. 
Immediately below each gear, as shown in the view, are 
placed the letters A-B-C-D. The first column of a lettered table 
placed in the upper right-hand corner shows that similar cones of 
gears are used on machines, size 2, 3, 4, and 5. The next column 
gives the number of teeth and the pitch of the teeth required in 
the gears A~B-C-D for the various sizes of machines. The 
remaining columns of the table give the outside diameter of each 
gear and its width of face. From this single section view, supple- 
mented by the lettered table, the machinist should be able to get 
all the essential information for making these gears, with the 
exception of the hole diameter, which is not given. The two 
smaller cone gears are shown as if made from a plain steel blank, 
while the two larger gears plainly show that they have a distinct 
hub and rim with a thin web connection. 

PLATE XVI 

FACE GEAR 

The two views of a special face gear shown in Plate XVI are 
half size in the original blueprint. The term "face gear" indicates 
that the piece represented is the large driving gear on the main 
spindle of the machine. While no finish / marks are found on 
the working lines of this blueprint, the average machinist would 
know that the outer diameter, the ends of the hubs, the holes 
through the gear, and the sides of the rim should be carefully and 
well finished. In addition to this, a lettered note at the upper 
right of the front view states that the surfaces indicated by the 
arrow points are rough turned. The title plate informs us that 
one is required and that the material is cast iron, which is also 
indicated by the arrangement of the cross-section lines in the 
front view. 

The view looking toward the end of the gear hub shows that 
the ujjper small hub has a short supporting flange and that on its 
lower edge the upper hub is counterweighted. A lettered note 
placed just at the left of the front view tells us that the hole in 
the hub is keyseated if inch deep and | inch wide and that the 
key is dovetailed and drives into place. Both views show the key 



/ / D.T.nZY — 7 /^ 
/ / naY DRIV£5 / / 






J) 



J?«L,i5"-l_„2|5 



'b\'M , ^^ 



■~'\-,BPtAK CORNERS 



JO RE NOT LE55 

THAN I" ^-f- 



nEYWAY g"WIDE 



D.T. KEY ----'. !■ 
nEY DRIVES 8^1^ 



h 




- A 

'.R0U6H 
'/ TURN 

1 


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87 T 6 P. Z0° PA. 



t4"^tymY ^^< 2i" M 

11 \ r t iJ^-r-r 



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AIAME OF PIECE AMI RLQ. NhML OF MACHINX PIECE NO 

DOWN FEED WORM-R.H.HEAD- ONE 3-n B0QIN6 MILL 14063 



j"P-i LEAD 
L.H.THRtAD 



'fj-'8"\\ 



WA5HER # 05710 ,2- WD5 PER INCH R.H. ^^ 

WASHER #05700 WAiHER5 #05703 K * 05710 '^ ^' DRILL-pi DEEP - 2 HOLES 

TO SUIT NUT # IBII5 DRILL IN POSITION 



GROUP NO. TRACED BY DATE CHECKED '"' CINCINNATI MATERIAL USE RATI NO. 5IZE LENQTH 

'ii%'o Kjillhom U0.I7 ^ PLANER CO. M.S. ^"ftOD %'" 



BLUEPRINT READING 33 

in place. Another important lettered note states that there are 
eighty-seven teeth milled into the outer face of the piece and that 
they are to be six pitch. The workman should especially note that 
the over-all diameter is to be held to definite limits of tolerance. 

PLATE XVII 
DOWN-FEED WORM 

The upper title plate states that the piece shown in Plate 
XVII is a down-feed worm for a 5-foot boring mill. One is 
required and the lower title plate gives the material as machinery 
steel cut from 3-|-inch rod 13| inches long, rough dimensions. 
Two views are given, with the front view sectioned to indicate 
steel. All dimensions are given on the front view. The end view 
is sufficient to show that in general the piece has circular outlines. 
The end view also shows the shape of the two kej^ways and, while 
no direct dimensions are given, this view shows the general position 
of the holes mentioned in the lettered note, "\" drill-|" deep- 
2 holes-drill in position". 

In considering this piece of work, the machinist is, of course, 
first concerned with the reamed l|-inch hole through its length. 
After this hole is finished ready for the mandrel, he should care- 
fully read all the notes and other lettered directions before begin- 
ning to square up and turn the piece. He should especially 
observe what surfaces are to be ground and give careful attention 
to the finished dimensions. He will note that certain dimensions 
have a small limiting tolerance given in thousandths of an inch. 
He should also note that, while the fine-pitch thread shown on the 
right end of the front view is a right-handed thread cut to suit a 
certain nut, the coarse-pitch 29-degree worm thread is to be cut 
left-handed. All dimension lines, figures, and extension lines are 
very clear and are easily located in reference to their working 
lines. The lettered notes have clearly defined arrow points to 
indicate the surfaces to which they refer. Attention is called to the 
diameter dimension reading "2^1 inches neck". This shows that 
the piece is to be necked in to this diameter previous to grinding 
the 2^-inch diameter as a protection to the corner of the grind- 
ing wheel. No finish / marks are shown, as the piece is finished 
all over, and this fact has been indicated by the initial letters 



34 BLUEPRINT READING 

F.A.O. placed just below the front view. The j^- 
ing just to the left of the flange collar should be drilled before 
cutting the keyway to give a clearance for the cutting point of 
the key seating tool. 

PLATE XVIII 
SADDLE ADJUSTING LEVER 
Plate XVIII, an assembly blueprint, is for the use of the 
setting-up machinist and clearly indicates how the group of parts 
which make up the saddle adjusting lever are assembled. It will 
be noted that each pin, cap screw, set screw, spring, lever arm, 
sleeve, etc., is given a part number and that an arrow point 
clearly indicates the part referred to. The arrangement of the 
cross-sectioning lines in the top view clearly indicates the material 
of each part; for example, they show that the lever arm ^lJ^2Jf.9 
and its hub are cast iron, while the handle screwed into its upper 
end is of steel. While the shape and position of each part of this 
mechanism are clearly shown in this blueprint, no dimensions are 
given, which shows us that, as previously stated, the print is to be 
used in the shop only by the assembler. The reader in studying 
this blueprint should consider that he is to assemble the various 
parts and endeavor to decide in what order they should be 
assembled: for example, it is clear that if 201 97, 02268, and 20180 
must be placed in position in ^lJf.2J,.9 previous to screwing j^^O^^^ 
into it; also that "If 142^9 must be placed in position on §1J^2IS 
previous to attaching cover plate ^lIf.2Jj.6. 

PLATE XIX 

TOP PULLEY BRACKET 

The top title plate informs us that the several views shown in 
Plate XIX are of a top pulley bracket for a 5-foot boring mill and 
that two are required. The lower title plate states that the mate- 
rial is cast iron. The views are a front view, a right side view, 
and a top view, which is in this case projected and positioned just 
above the right side view. The arrangement of full and dotted 
lines indicates that the piece consists of a hollow base, or pedestal, 
having at its upper end a shaft-carrying box, or bearing, which, in 
turn, has a large grease, or oil, pocket on its upper side. 



NAMt or GROUP AMT RtQ /<AME OF MACtllNJ. 6R0UP NC 

SADDLE ADJUSTING LEV£R 4. 5FT BORING MILL 14014 



yArMyAMyy////y//A 




^9SK!l!/momKeO^)SO^iOii7X09X>i9i^X!9i^i9. 



5^1 SCHEW Naoo 



14248 RATCHET FOU mO SHAFT— '^ 
14247 RATCHCT FOR RAIL SCREW--' 



02119 /f£Y FOR FitD SMAFT-^ 
02157 KfY FOR RAIL 5CR£W 





6R0UP NO. I DATE I CHECKED f'ClNCINMATl MATE5IAL USE PATT NO SIZE LENGTH 

14014 01117 ^ PLANER CO. 



f'iAML or PIECE 

TOP PULUY BRACKET 



AMI. REQ. Hkm. or MACHINE PIECE Ntt 

2 5-rT BORING MILL 14200 



xssm^^t 






'^8 " ~^^i'i^J~^r6^' 



. r-'f -A 



^^ -f , — 

J ' ' 



zr^z-j 



. 4i" — ^ 




SROUP NO. I DATE I CHECKED P"' CliNCIN/SATI I MATERIAL U5EPATT.N0. 51ZE LEN6TH 

"T''5.«i7 ^ PLANER CO. C.I. 



BLUEPRINT READING 35 

In reading this blueprint, the machinist should observe that 
many of the dimensions given are for the use of the pattern maker 
and are of no especial concern to him. The pattern maker, on the 
other hand, is concerned with all the dimensions as he must add 
sufficient stock to every surface marked with an / to allow excess 
metal for the machinist's purposes. As an instance of this, take 
some of the dimensions as given on the front view and the right side 
view. We observe that at the extreme right hand of the side view 
a dimension of 14 inches is given from the lower line, or base, of the 
pedestal bracket to the center line of the box. While this is a 
dimension for the machinist in particular, the pattern maker must 
also note that the base surface is to be finished and make the 
dimension enough longer than 14 inches so that the machinist will 
have metal stock sufficient to allow Mm to finish the base surface 
and still have the correct dimension. Also, in considering the 
shaft hole given as 3| inches ream, the pattern maker must make 
his core prints and core boxes enough less than 3| inches in 
diameter to allow stock for machining the hole to the specified size. 
The pattern maker only is concerned with the dimension | inch 
given for the wall thickness of the hollow pedestal and that of 9j 
inches given at the bottom of the side view for the width of the 
pedestal. These and many other dimensions are not subjected to 
any machining. The pattern maker, then, in reading this blueprint 
will carefully consider each and every working line, whether 
drawn full to represent a visible outside surface or drawn dotted 
to represent an invisible inside surface, in order to give himself a 
dear mental picture of the construction not only of the outer out- 
lines of the piece but also of all the interior outlines. WTien the 
pattern maker has this clear mental picture of the piece, he can 
then readily trace the dimensions of all parts of his construction 
by following the extension lines. 

If the pattern maker has fully understood the views up to this 
point he clearly sees: (a) that they represent a ring oiling pedestal 
bracket with the base cored out to leave walls I iuch thick, the 
cored portion to extend up from the base line of the bracket to 
within ^ inch of the bottom surface of the cored oil chamber; 
(b) that the cored oil chamber is 4\ inches in length in a direction 
across the shaft bearing and l\ inches in width along the shaft 



36 BLUEPRINT READING 

hole, and that the oil chamber extends out toward the front of the 
bracket into a rounded-end projection, or lug; (c) that he must 
provide a loose pad on the front of the pedestal, as shown, "for 
belt drive only"; and (d) that the bottom surface of the bracket, 
the entire hole through the bracket box, the upper surfaces of the 
oil pocket, and the front face of the bracket pad are to be machined 
as indicated by finish / marks, and that excess stock for machining 
off must be allowed on such surfaces. 

The machinist in reading the views should carefully note 
which surfaces are marked with the finish mark for machining. 
Starting at the pedestal base, as shown in the front and the side 
views, he will observe that its lower surface is to be machined and 
that certain holes are to pass through it. A study of the top view 
and its lettered notes shows that there are to be three holes through 
the base in each of its ends. Two of each three are drilled for 
holding-down bolts and one for No. 8 locating taper pins. The 
holding-down bolt' holes are to be spot faced for the heads of 
the bolts. 

Returning to a study of the front and side views, the 
machinist notes that the front surface of the pad is to be 
machined. This surface, as shown in the side view, is 4| inches 
from the vertical center line. Four f-inch tapped holes are to be 
drilled into the face of the pad 3| inches apart along the horizon- 
tal distance and 2^ inches apart in the vertical dimension. Before 
machining the shaft bearing shown at the upper part of the front 
and the side views, the machinist should note: (a) that the bear- 
ing proper extends in length from the inner edge of a narrow cir- 
cular oil-collecting pocket to the inner edge of a similar opposite 
circular oil-collecting pocket and that this bearing surface is bored 
and reamed to a diameter of 3| inches; (b) that outside of the cir- 
cular oil-collecting pockets, the hole diameter is increased to 3^ 
inches; (c) that while the circular oil-collecting pockets are marked 
/ and afe therefore to be machined, no dimensions are given, this 
indicating that they are simply machined to remove the original scale 
and to make them truly circular; and (d) that a large central oil- 
containing chamber is provided for an oil-conveying ring and that 
two oil-return holes are drilled from the edges of the two circular 
oil-collecting pockets at an angle which allows them to enter the 



jmRO AN6Lt -PQOJtCllON 






^^U"""4%\ j^tt, 





< 4' 


<-^/'=t 






«-^"-^ 
A 








\^\' 


W 








1 1 





i"-IO JAP 
iS" DIA. SPOT FACE 
3 HOLES 



/ /V/i"-4^'"->i\ Al- 



-8" DRILL- 4 HOLES 



SECTION A-B 




3 3392S3 3M/W(/57WS SC*f)V 



3 57ffiL Z-690// ? A6 



PEDESTAL 

FIR5T MADE FDH. A/ijrO,?; IND.-ni.205 



v»Vi\%xi^mvkim'Mniwi 



THIRD ANGLE PROJECTION 



-5.000'tf^i; 



a-5?TAPiwP /.7/^--'-^" 

^- HOLES ( r;y^ r 



■ 18^0" DIA C-12} DRILL 
SLIGHTLY C.S FOR RIVETING 



. Z2&« (*lj DRILL 
I ZHOLEi l«DIA 
C.B x^"DCiP 




-i I ^1 



-2l" > 



\\^>ev■ 




Z 69018 W K Ca WAJH. PLAIN SPO. Ju rYt 

1 W[mi&imm TsrS A-12 



I \e\MCH.5Cli.'l2-24xl'L0 



6 \M5[MBLy OF PARTS 'Ui 



m7.90i \A-\PIN FOR 



LND SHIELD 

IriRST MADE FDR WTOI? DSP n26 RC6. 5W. 15974 



MN. n- im \CHV.1tlOINCI\Ti(DIM.0F#l 



BLUEPRINT READING 37 

central oil-containing chamber, the letterea note stating that these 
oil holes are ? inch in diameter. Two threaded holes are shown 
through, the upper shell of the shaft-bearing box and a note 
attached by a line and an arrow point to the upper view explains 
that they are to be drilled y| inch for a |-inch tap. Finally, the 
upper surfaces of the oil box are marked / to be machined. 

PLATE XX 

SHAFT-BEARINQ PEDESTAL 

Plate XX shows a shaft-bearing pedestal in which the shaft- 
bearing box is a separate unit (not shown) which may be supported 
inside the pedestal. As the shaft-bearing box would be held 
exactly central with the frame of the pedestal, many of the work- 
ing lines of the left side view are drawn around the center line, or 
axis, and several of the dimensions are figured as a radius from a 
common center. The views consist of a front, or edge, view, a 
left side view, and two smaller views, one of which is a section on 
line A-B and the other is placed just below the side view and 
shows a bottom \'iew of the feet of the pedestal. 

Very little machine work is to be done on this piece, merely 
machining the base supports on their under surface, drilling holes in 
the feet for four holding-down bolts, and drilling, tapping, and 
spot facing the three prominent bosses. It will be noted by the 
machinist that the latter holes are at an angle of 120 degrees with 
one another. The machinist should also observe that the base 
supports are to be finished to give their under surface a distance 
of 9^ inches from the center line, or axis, of the views. Practi- 
cally all the remaining dimensions are given for the pattern 
maker's use and are easily located and read. 

PLATE XXI 
END SHIELD 

In reading the front view, the small view, and the right end 
view of Plate XXI, the reader should clearly see that when he 
looks at the right end view, he is in fact viewing this end shield at 
its large open end. A study of the front section view shows that 
the casting essentially consists of a large cup-shaped portion at 
the right with only a rim bottom. A half rim is attached and 



38 BLUEPRINT READING 

projects to the left and carries a circular hub having a circular 
hole of two diameters. In this blueprint the machinist, to under- 
stand the views, must carefully follow each working line of the draw- 
ing, locate each extension line, and note each arrow-pointed line. 
All the important finished dimensions are given a limiting tol- 
erance in thousandths of an inch. The rim edge of the large cup 
shown at the right of the front section view is finished to a 5.250- 
inch diameter and 0.094-inch depth; and three holes through the 
rim bottom are also finished. Two of these holes, 4x1 inches cen- 
ter to center, are counterbored for fillister-head cap screws, while 
the third hole, showing at the top of both views 2| inches up 
from the center line, is countersunk for riveting. A detail of this 
is given on the lower side of the blueprint. The circular hub 
which shows at the left of the front section view is machined on 
its outer end and a double-diameter hole is finished through it. 
Four holes are drilled and tapped into the outer face of the hub. 
A lettered note placed slightly to the left and above the hub gives 
the necessary information for these holes. 

PLATE XXII 

ARMATURE HEAD 

Plate XXII is a combined assembly and detail blueprint and 
according to the title plate is made up of (T) armature head 
assembly, (D armature head, and (|) stud (fan-supporting), the 
whole being given the title plate name armature head. The num- 
bers 1, 2, and 3 are clearly shown in the blueprint placed near or 
on the views. The material of the stud is given in the title plate 
as cold rolled steel and that of the armature head as soft steel 
casting. The front view is shown in section on line A-B-C. The 
careful reader will note that section line A-B-C follows the 
vertical center line of the right side view from A at its lower 
edge to B at the center axis and then slants to the right and 
upward, ' following the center line of one of the three ribs to C. 

Stud. A study of the front and the end views shows that the 
studs (D (also shown at the upper right of the blueprint) are 
screwed into the three ribs just mentioned, and a lettered note 
placed on the sectioned front view states that they are machined 
to a bevel after assembling. 



I 

I 



A- 0.0005" 

e= 0.0 or 

r- no02' 
D-- U.0 05" 



THIRD AN6U PROJECTION 



SECTION A-fi. 



.V ^^^o^-HK— 3o°. 



<^— fd=r--A~>- 



i^-'i^y 




Wf 



14-24 THQEAD 3,, 



'» *\ DIA. 



^14-24 TAP 
3- HOL£S 



SECTION A-B-C 



\3\5mLC.R.\ V \5\5TUD (FAN SUPPOKTINB) 



wsofnpAnaM2S6-£ 2 ARmiuRt hud 

1 ] \ARMAWeC HEAD A5itMBLY 



, . ARMATURE HEAD (Fan Em) 

t-p FIP,ST MADE FOR AWTOB CVC-III- 



zT/l^A'™f'°•M•l,ooo,o9^-lo. 



THIRD AN6L£ PROJECTION 



as HOLES, EQUALLY 
>\ SPACtD 



PUNCHED 


PART 


COPPER 5n. HARD 
.IZ5'TH 


MATtRlAL 




PRINT5 TO- 
9 




OP 






^ll"SAW CUT 



,/> 



/i" SAW CUT' 



® i-. 002' MAX. 
\ -.002' MIN. 




SECTION AB 1 




^(D FEB. 24-09 yy,,, , 
CH'D DATE A A I I I - / 



FIRST MADE FOR 
MOTOR GEN SET M.I.C 
3 nw- 1800- 440/125 
RE6.N- 99438 , 



ARMATURE END RING 

EENERAL ELECTRIC CO., LYNN. MASS. 
oATt ocT.aoa 343066 



BLUEPRINT READING 39 

A small detail section A-A placed just over the center of the 
side view shows the form of the slot on the section line A-A 
drawn across the upper edge of the side view. These slots, 
twelve 'in number, are shown by dotted working lines in the side 
view and are spaced evenly completely around the armature head 
at its extreme left end as the piece is shown in the front view. 

Careful study of the views shows that the armature head 
casting is a circular cup having three narrow shallow ribs cast 
onto the inner side of its rim. It is into the outer ends of these 
ribs that the cold rolled steel studs are screwed, as shown. At 
the opposite, or base, end of the casting is located the outer flange 
for the slots shown in the detail section A-A. Extension lines 
drawn from the working lines of the flange carry a dimension line 
and arrow points which show that the flange diameter is 4f 
inches. The body rim of the casting is to be finished to an out- 
side diameter of 4| inches. The hole through the hub of the cast- 
ing, it should be noted, is finished to a diameter of 1.375 inches, with 
a tolerance of but one-half of one-thousandth inch above size and 
no tolerance below the figured diameter. The keyway is figured in 
the side view as being J inch wide and -^ inch deep. It must be 
noted that the keyway is located in the hub hole on the center 
line of a rib and not in the thinner part of the hub. The reader 
should observe that the radius of the rim side of the 4|-inch flange 
is curved to a f-inch radius as shown at the upper left of the 
front view and that a corresponding radius of ^ inch for the flange 
slots is shown at the lower left of the front view. The centers for 
these radius lines are shown as 2 inches from the center line of the 
piece and J inch from the edge of the piece. A lettered note 
placed just below the side view gives the tapped stud holes as 
14-24 tap-3 holes. The hole in the outer end of the stud is given 
as 10-32 tap-f inch deep. 

PLATE XXIII, Nos. 1 and 2 

DETAILS OF TYPICAL ARMATURE PUNCHINQS 

General Data. Plate XXIII is made up of two D-size prints, 

each giving the details of a separate piece. For convenience in 

referring to them they have been given the numbers 1 and 2. 

Two other illustrations of a like construction are shown in Plate 



40 BLUEPRINT READING 

XXIV. The pieces represented are punchings from sheet steel 
or sheet copper. The reader will note that a single complete 
view of each piece is shown supplemented by section details. 
The complete views, with the exception of blueprint No. 2 on 
Plate XXIV, are drawn to one-half scale in the original blueprint 
and the detail section views, in the original, are made to an 
enlarged scale about double size. These enlarged details show 
the form, size, and kind of holes to be made near the outer 
edge of the punching, as shown at the right of the complete 
views. A lettered note resting on an arrow states that there are 
to be eighty-three holes equally spaced around the punching. 

Armature End Ring. The title plate gives blueprint No. 1 as 
an armature end ring punched from hard sheet copper 0.125 inch 
thick. The holes and the entire punching are made by using 
what is known as a perforating and shearing punch and die. The 
metal punched out of the hole, in this case, is turned, or bent, 
inward as shown in the enlarged details. A note with two arrow 
pointers tells us that this punching has two x^-inch saw cuts. 

Armature Punching. Blueprint No. 2 is an armature punch- 
ing punched from standard quality soft sheet steel 0.014 inch 
thick. A single view shows the complete punching. It has a 
7-inch hole of a maximum tolerance of 0.001 inch above size and 
the outside diameter is 10.960 inches with a minimum tolerance of 
0.006 inch. The punching is provided with a keyway J inch wide 
and il inch deep. The outer rim is provided with eighty-three slotted 
holes equally spaced around the circumference. An enlarged view 
of these slots is placed just to the right of the complete view. 
Lettered notes with arrowhead pointers give all the slot dimensions. 

PLATE XXIV, Nos. 1 and 2 
DETAILS OF TYPICAL FIELD PUNCHINGS 
Field Punching. In Plate XXIV are shown two blueprints of 
which No. 1 is a field punching punched from soft sheet steel, 
standard quality, 0.014 inch thick. One complete view only is 
given but, as in the blueprints shown in Plate XXIII, there is an 
enlarged view of the slots. This enlarged view gives complete 
details of the slots and the exact dimensions with all hmiting tol- 
erances. A note placed below the complete view tells us that the 




l-'^C^i »v4^!r-S"H.--Vit#3J>-a.v. 




A- 0.0005" 
6 = 0.001" 
C ' 0C02' 
D ' 0.005" 



Wm ANGLE PROJECTION 



_^ >|< _ 



S/M/LAP TO PUNCH 10154 







PUNCHTD PART 

57m SHEET son MATERIAL 
STANDARD QUALITY 
.014" THICK 

PRINTS TO- 
49 
9 

OP 
38' 
iSA 

21 

b 

142 



^,if.002"MAX. \ 



U Ui^ 




i + .002"MAX./ 



„-f.002"MAX. 



^APRZfBII 

[,r)JUNE?5-10 YYI\/ 1 

CUD DATt A A I V - 1 



MOTOR IND.KI FRAME 

#I40A-C24^ 
REG. 1372615 i 
DRAWN BY Purinfon 



FIELD PUNCHING 
GENERAL ELEETRIC CD., LYNN. MASS. 

DATt OCT FS -08 545089 



THIRD ANSLC PROJECTION 



A. 005" MAX.. 




PUNCH LD PART 

Sff££T 5T£EL MATERIAL 
COM. QUALITY 
.062?" THICK 

PRINTS TO- 
9 



FIRST MADE FOR 
MOrOJ? CR^A. 



POLL PIECE. LAMINATION 



DRAWN BY 5. Ackerleu DATE OCT 15 '06 





i<- — 3^" — >. 
'■ BORE 
18 T0N5 FORCE FIT 



n ALTER PAJTFRN 
A 9573 K 



TOTAL DEPTH 
OF CUT .5i9''t 



48- TEETH- HOBBED 14^° INV. 
4 DIA. PITCH 
12" PITCH DIA. 






Z4-TEETH- HOBBED 14^° INV. 
5 DIA. PITCH 



■BILL OF MATERIAL- 
MARK NO.tWDl 5T0CK | DESCRIPTION 


/\ 










iO-.tO'UCMI 

RON m-HO'L 
MAHO. TO K 

THORW 

*N>JCMED 

C.H. inn PINION 

foRom 

X-iO'l. C 






B 


/ 







12" MERCHANT MILL 

CONNECTING TABLE BETWEEN 21" £( 3"-° PAIRS 

GEARS 

SCALE 6'f'l'.^ 

CONTRACT BETH. ST. CO. -iA ^^] 

DATE 3- 7- 17 ii la^ 

DR G.PM. CM. Sffff. 

TR. W.FJ. APR ef2 L 

FROM 

MORGAN CONSTRUCTION CO. 

WORCESTER, MASS. q 22313 



BLUEPRINT READING 41 

slots are thirty-six in number. The punching has four lugs on 
its rim placed 90 degrees apart. The outer contour of each lug, 
the careful reader will observe, is made up of arcs of circles con- 
nected by short straight lines drawn tangent to the arcs. This gives 
an irregular outline to the lugs. The die maker will, of course, 
note that many of the dimensions for this punching are exact to 
quite small limiting tolerances. 

Pole Piece Lamination. Blueprint No. 2 is a pole piece lam- 
ination, and the upper note informs us that it is punched from 
sheet steel, common quality, 0.0625 inch thick. When the reader 
considers the thickness dimensions of the punchings shown in 
Plates XXIII and XXIV, he will readily see why an edge view is 
not given except at an enlarged scale, as in the several detail 
views. Plate XXIV, No. 2, is drawn full scale in the original 
blueprint. Only two dimensions show limiting tolerances. Most 
of the radius lines are from a common center placed somewhat 
above the view and on its center line. Centers for the other 
radius lines are clearly defined by small circles inclosing the center 
points. Radius lines are clearly drawn and dimensioned with the 
arrow points touching the working lines of the view. The die 
maker should carefully locate that part of the working line to 
which each radius line refers. 

PLATE XXV 
GEARS USED ON 12=INCH MERCHANT MILL 

The title plate tells us that Plate XXV shows gears used on a 
12-inch merchant mill. The bill of material states that one of 
these is made from steel casting thoroughly annealed and the other 
from an open-hearth steel forging. In the original blueprint the 
views are drawn to a scale of 6 inches to 1 foot. Where two 
gears are shown and one is larger than the other, the smaller of 
the two is the pinion and the larger is the gear, and in reading 
this blueprint they will be referred to in this way. 

The pinion is shown in two views, with the front view in sec- 
tion as if sliced through the center of its length. The end view 
at the left of the front view clearly shows the hole and its keyway 
through the pinion; other than this, it consists of three concentric 
circles representing the outside diameter, the pitch diameter, and 



42 BLUEPRINT READING 

the root diameter of the pinion teeth. A lettered note placed 
just beneath the views tells the machinist that the pinion is to 
be hobbed and has twenty-four teeth of the regular 14|-degree 
involute form, five diameter pitch. The term diameter pitch refers 
the pitch of the teeth to the pitch diameter of the gear. Finish / 
marks show that the pinion is to be finished all over. 

The views of the gear are arranged similarly to those of the 
pinion. Finish / marks show that the ends of the hub, the sides 
of the rim, the outer diameter of the rim, and the hole through 
the center are to be machined and that the inside of the gear rim 
on both its ends is chamfered as shown. The machinist should 
carefully note that the hole through the hub is bored 3^^ inches in 
diameter and that the gear is to be forced onto its shaft with a 
pressure of 18 tons. The machinist should also observe that there 
are forty-eight 14|-degree involute teeth in the gear and that they 
are to be cut on a gear-hobbing machine. The pattern maker 
should especially note that there are six holes cored through the 
web of the gear. All dimensions and extension lines are clearly 
and plainly defined and so placed as to be easily read. 

PLATE XXVI 

BEVEL GEARS FOR ROLLS ON SHEET BAR AND SLAB=MILL 
STEAM FLYING SHEAR TABLE 

The title plate of Plate XXVI informs us that the views 
shown represent a pair of bevel gears used on a 21-inch sheet bar 
and slab mill steam flying shear table. The bill of material shows 
them to be open-hearth steel castings thoroughly annealed. The 
front view of the gears is sectioned by a plane along their axes 
and shows the gear and the pinion with their teeth engaging, or in 
mesh as it is called. A pair of bevel gears are usually shown thus, 
and the reader should make himself familiar with this fact and 
should study every detail. The end view of the pinion and the 
end view of the gear are just sufficiently complete to show the 
hubs and the holes and keyways through the hubs. 

A lettered note A states the number of teeth in the pinion, 
the form of the teeth, the pitch of the teeth, and how they are to 
be machined. A lettered note B gives like information for the 
gear. When reading these lettered notes, the machinist should 




TIOHT FIT ON 2ll" SffAl^ 



'TAPeeg'Pfen'' 







/9 m/S/flD TEETH 
PLANED TO 20" INVO, 
it cm. PITCH 
9.072" FITCH DIA. 
9.705" OUT DIA. 



30riNI5flED TEETH 
PLANED TO 20°IW0Ll/T£ 
it CIR. PITCH 
14.324" PITCH DIA. 
14 7Zy OUT DIA. 




■BILL OF MATERIAL- 1 






markIho.req'd 


STOCn DESCRIPTION 


A / 


O.tl.STUL GEAR 


B i 


SMOOTH GEAR 
CASTING 
50-60%C..60- 
SO'/.MANOJH- 
OROUOHLf ANNC UCD 



21" SHEET BAR A SLAB MILL- STEAM FLYIN6 
SHEAR TABLE-BEVEL GEARS FOR ROLLS 



5CALE 6 '« = /''J 

CONTRACT SHARON 5.H.C0. 






DATE 3-12-18 

OR. W.B.5. zn.Aie' 

TR. L.B.E). APP.ii&€" 



MORGAN! CONSTRUCTION CO . 

WORCESTER, MASS. g 23162 



BLUEPRINT READING 43 

not fail to observe that the gear teeth are 20 degrees involute 
instead of the ordinary 14| degrees, also that the pitch of the 
teeth is given as circular pitch instead of the more common 
diameter' pitch. Circular pitch is the distance from the center 
line of a tooth to the center line of the next tooth and is measured 
along the pitch circle. In bevel gearing, it is measured at the 
largest pitch diameter. 

The machinist, after carefully reading the lettered notes, is 
next concerned with the holes through the hubs of the gear and of 
the pinion. He will note that the gear is to be forced onto its 
shaft wdth a pressure of 15 tons and that in the pinion the hole 
should be a tight fit on the shaft. He will also observe that each 
keyway is to taper at the rate of | inch per foot. The machin- 
ist's next concern is the outside diameters of the gear and of the 
pinion. By following the extension lines to their dimension lines 
he learns that the gear is 14.725 inches and the pinion 9.705 inches 
outside diameter. He then locates the angles which give him the 
cone form of the pinion and the gear blank and notes that they 
are given in degrees and minutes. By using a bevel protractor in 
his measurements he can readily machine the cone sides and edges 
to the required angles as given on the blueprint. Making the 
length of the tooth an even 3 inches as given completes the pinion 
and the gear blanks (so far as the tooth rims are concerned) ready 
"or cutting the teeth. The back end of each hub is faced up and 
'.ts end circumference is machined into a circular groove of definite 
dimensions which are easily found and noted. 

Previous to planing the teeth, the machinist should locate the 
angle marking the bottom of the tooth space. This angle is 
known as the cutting angle, and in this blueprint the reader will 
find it for both gear and pinion near where the center lines of the 
gear and the pinion cross each other. For the gear, the cutting 
angle is 54 degrees 37 minutes and for the pinion it is 29 degrees 
19 minutes. The total depth measured at the outer end of the 
teeth should be noted. This is given as f inch+0.45 inch. As such 
gears as these are usually planed on a special gear-tooth planer, no 
further directions need to be given. The pattern maker will find 
in this blueprint aU the necessary dimension lines, radius lines, 
and figured angles for a complete pattern for each gear. 



44 BLUEPRINT READING 

PLATE XXVII 

MOTOR COUPLING FOR ROD MILL DRIVE 

Plate XXVII shows the parts of a motor coupUng for a rod 
mill drive. The bill of material notes six parts A-B-C-D-E-F 
and gives the material from which each part is made and the 
number of each required. In the original blueprint all the views 
are one-quarter size, 3 inches to 1 foot. Lettered note 1 gives 
special shipping directions, and a most important note placed in the 
center of the end view gives explicit directions regarding the size 
of the hole and states that it is to be shrunk on the motor shaft. 
The front view of the coupling body A is sectioned through the center 
of its length. For the pattern maker, this is a simple job and he 
can make no mistakes in finding his dimension lines and figures. 

The machinist who carefully reads the views will note that 
many of his dimensions are given to a special fixed gage. The note 
on the end view states that the hole is to be bored 0.007 inch 
small to allow a shrink fit. The keyway in the side of the hole 
is to be tapered | inch per foot. A note at the hub end of the 
front view shows that this end of the hole is to be chamfered. 

There are two hole keyways if inch deep at the deeper end 
and a broad shallow keyway across the face of the flange part of 
the coupling, 1| inches deep and 3| inches wide to gage. Finish / 
marks on the working lines of both views indicate that the piece 
is machined all over. The smaller details of the coupling B-C-F 
are given near the right end of the blueprint. F shows two views - 
of the key which fits the broad keyway machined across the face 
of the coupling flange; one end of the key is curved, as shown, to a 
radius of 10| inches. A Ij^-inch hole is shown drilled near the 
curved end and this helps us to understand that a flange bolt B 
passes through this end of the key when it is fitted in place in the 
face pf the flange. The width dimension shows that it is to gage. 
The flange coupling bolts B with their nuts C are shown by a front 
and an end view. The front view shows the nut C in place, 
which is a common way of showing bolts and nuts. A hole is 
shown drilled through the body of the bolt near its threaded point 
for a -^-inch cotter pin. The end view gives the shape of the bolt 
head and nut and shows it is chamfered at its outer corners. 



|"OT/u roR E \ 
. ''"IP, C in 



41 ^ ^ 




DIA. BOLT emeu WITH 6 HOLES /M'DM. 
DRILLED TO JI6 



•BILL OF MATERIAL- 



NOTtr- 5ENDAT0NCE TO UECTRICAL DEPARTMENT OF 
ALUS CHALMERS CO.. MILWAUI1EE. WIS. FOR 
THEIR ORDEB 2-£~4l36. A TEMPLATE FOR THE 
KEYWAVS AND A PIN OAUOE FOR THE BORE. 
LATEH SEND C0UPLIN6 TO SAME ADDRESS TO BE 
5HRUNK ON MOTOR SHAFT 



STECL Itm.comn z'lohg 



fa.U'M.1 •mESMilEuEM 



ALTERATION OF ROD MILL DRIVE 
DETAIL or MOTOR COUPLING 

5CALL 3'{''/':r C RlvistTH 

CONTRACT INTER. I & ST. CO. \ 

DATE i-iz-ia K 

DR. A.R.K. CH. A«X A 
TR. ».F.n. APR Lf 



B 22850 XXVII 



MORGAN CONSTRUCTION CO . 

WORCESTER, MASS g 22850 



COR£ 8-1" nous 
FOR A 18053 W 







--/— -L,i,,i,5. J — / 





■ \y- CAP A/S053£ 



OIL CHAIN AJ8059Y > 



'-;|"*2|">k I9i' 



f i^i- 



A 18053 C ' 
A ALTER PAlJtRN Aia059B 




^I'RIVET 
A 18059 U 



., l^JAP rOR i' PIPE 
j<-5i.ill — A PLUG A 18059 X 









DML 2-i'mL£S ^ 



FOR ONE HOT BED 
BILL OF MATERIAL 




21" 5HEET BAR &( SLAB MILL 

COOLING BE05 

BINDER ARM FOR ROPE TAKE-UP 

SCALE J'-'W-f 

CONTRACT Sn/ 

DATE ■4■■^^-la 

DR J.M.M. O- 

TR, /?W AF..-^_- 

FROM 

MORGAN CONSTRUCTI ON CO. 

B 23188 



BLUEPRINT READING 45 

PLATE XXVIII 

BINDER ARM FOR ROPE TAKE=UP 

The> title plate shows that the views in Plate XXVIII are of a 
binder arm for rope take-up used on the cooling beds of a 21-inch 
sheet bar and slab mill. A long bill of materials is given. The 
title also tells us that in the original blueprint the views are drawn 
to a scale of 3 inches to 1 foot. 

The views are complete and this is a very interesting blue- 
print for either a pattern maker or a machinist. For example, the 
reader will note that at the right-hand upper part of the front 
view the bearing cap is shown in place on its bearing by a series 
of dash and dot lines known as broken lines. This gives a sort of 
skeleton view of the cap. At the same place is a skeleton view of a 
bushing marked A18059F. Looking this number up in the bill of 
materials, the reader finds that the bushing is made of lumen 
bronze and that eight are required for four binder arms. Directly 
below this part of the view and at its extreme lower edge, similar 
skeleton views are shown of a cap A18059C and a bushing A18059D. 
In looking for these numbers in the bill of materials, the reader 
finds the names of the parts, the material used, and the number 
required for four binder arms. When the reader has carefully 
located each part in the bill of materials, he should consider its 
name, the number required, and the material used. The bill of 
materials shows that the binder arm is marked A, that it is made 
from a steel casting, and that four are required. 

Another interesting matter relating to this blueprint is the 
method used in sectioning various parts of the views to open up 
the bearings clearly to the reader. A bottom view of the lower 
bearing is shown placed just below the side view and a similar top 
view of the upper bearing is placed just above the left side of the 
front view. The machinist must finish the four bearings to fit the 
caps and the lumen bronze bushings and drill a pin hole Sff inches 
in diameter for A18070G through the length of two circular hubs 
plainly showing in the lower half of the front and the side views. 
In addition, he must drill a ^-inch oil hole in the upper part of 
the lower bearing and a hole just below each of the upper bear- 
ing and tap for a |-inch pipe plug. The machinist will also note 
tha,t both ends of all four bearings and the inner ends of the pin 



46 BLUEPRINT READING 

hubs are finished and that a spring brass wiper is riveted into each 
of the upper boxes near its inner end. 

The pattern maker will note that the framework of the piece 
is a simple rib construction for supporting tlie several bearings and 
hubs and that the working lines are well dimensioned. 

The upper bearings are complicated by having to be cored for 
an oil well, or chamber. The oil in this chamber is distributed to 
the shaft by means of a tinned steel universal chain A18059Y 
hung on the shaft into the enlarged part of the center of the oil 
chamber. The pattern maker should also note the special cored 
holes through the outer and the inner ribs showing just below the 
long pin hubs. Finish / marks placed across certain working lines 
of the view show the pattern maker for which surfaces he must 
allow an excess of metal for the machinist's needs. The bolt holes 
in the upper bearings for A18059W are cored, while those in the 
lower bearings for A18059V are drilled by the machinist. 

PLATE XXIX 

PARTS OF SHUTTLE MECHANISM FOR LOOM 
Plates XXIX, XXX, and XXXI are each made up of four 
small blueprints originally 4|"X5|" and show the practice of the 
Crompton-Knowles Loom Company. The small 4|"X5f" blue- 
prints are those used in their shops as working blueprints. Each 
small blueprint is from a free-hand sketch of some part of one of 
their machines and contains ail that the workman needs to know 
when machining the piece. Blueprints made like those which we 
have been studying are used by the pattern maker. 

A number placed in a circle has been added to each small 
blueprint to make it easy to refer to and each is provided wdth a 
title plate which contains certain information useful to the work- 
man. For example, the title plate of the small blueprint No. 1 tells 
us that the piece is a rocker iron for a shuttle change motion on a 
medium duck loom and that the material is cast iron. , Blueprint 
No. 2 shows the lower part of a shuttle carrier; No. 3, a stand 
for a lifter; and No. 4, the top part of a shuttle carrier. In many 
of these blueprints no over-all dimensions are given, and as they 
are not made to any particular scale of sizes, in such cases the 
sketch artist places the over-all length of the piece in the upper 



47 

for 

;his 
ires 
ure 
the 
ate 
ing 

!tO 

les. 
ine 
my 
or 
Drk 
.. 2 
3r" 
the 
:tle 
art 
ed. 



ir a 

in 

are 

ure 

the 

ue- 

on 

om 

md 

ich 

ods 

of 

les. 

led 



NO. 108152-3 



NO. 108156-9 




■-M^ 'I 



TITLL ROCKER IRON 

MOTION SHUTTLE CHANGE (LAY) 

FOR DETAIL SEE 



NO. 108/54-5 



LOOM MED. DUCK TITLE SHUTTLE CARRIER LOWER PART 

MATERIAL C.I. MOTION SHUTTLE CHANGER. 

DATE 4- 10- 18 FOR DETAIL SEE 



A NO. 108156- 7 



LOOM MED. DUCn 
MATERIAL CI. 
DATE 4- 12- 18 




TITLE STAND FOR LIFTER. ROD OLHDE LOOM MED. DUCK 

MOTION SHUTTLE CHAN6E v v . w MATERIAL G. I. 

FOR DETAIL SEE A A I X DATE 4-- 10- Id 




TITLE SHUTTLE CARRIER TOP PART 
MOTION SHUTTLE CHANGER. 
FOR DETAIL SEE 



LOOM . MED. DUCK 
MATERIAL C.L 
DATE 4- 12- IS 



TO r/T 80778-9 



TITLE STAND FOR GIAR GUARD 
MOTION CAM HAR MO. 
FORDtTAILSEE 




LOOM WEBBING 
MATERIAL C.I. 
DATE (b-15'ia 



l"HOL£5(^)oN (>l'>omca 









^-^i"f->\ ^i"^^'^^^ 



TITLE 5PI/R GEAR ON CRANK SHAFT 
MOTION DRIVE 
FOR DETAIL SEE 



LOOM SILh 

MATERIAL C.I. 
DATE 6- 18- 18 



^12-24- TAP FOR COLLAR 




TITLE HUB, FOR PULLEY 

MOTION DRIVE w w \/ 

TOR DETAIL SEE AAA 



Swivel 

108622-5 



LOOM PRF55 CLOTH 
MATERIAL C.I 
DATE 6- 25- 18 



::i_/^_:::: 



—^— 






TITLE 5PUR GEAR ON BOTTOM SHAFT 
MOTION DRIVE 
FOR. DETAIL SEE 



LOOM 51 in 

MATERIAL C.L 
DATE 6- la- 18 



BLUEPRINT READING 47 

.left-hand corner in small numerals over or on a short line; for 
l^xample, the piece in blueprint No. 1 is 21 inches long. While this 
dimension is of no value to the machinist, it does aid the stores 
keeper in handling the castmgs, for, while each sketch is a picture 
of the piece in so far as its outlines are concerned, unless the 
small numerals are read, there is nothing in the view to indicate 
whether the piece is inches or feet in length. While such working 
blueprints are not commonly used, it is worth the reader's while to 
study them, as they show very clearly the use of free-hand sketches. 
It must be borne in mind that in certain lines of machine 
building, while a given machine may consist of a great many 
parts, each part may be a very simple piece requiring but little or 
no machining; for example, blueprint No. 1 shows a piece of work 
that is to have four drilled holes, two of which are tapped; No. 2 
shows a piece with one drilled hole; No. 3 is marked "no labor" 
and shows a piece of work in which the holes are made in the 
foundry by the use of properly shaped cores; and No. 4 is a little 
more complicated, having two 3^-inch tapped holes 3j inches apart 
and one |-inch tapped hole with the end of the hole boss, faced. 

PLATE XXX 

DETAILS OF GEARED MECHANISM USED ON 
CROMPTON=KNOWLES LOOM 

In Plate XXX, blueprint No. 1, which represents a stand for a 
gear guard, is shown in the same manner as the blueprints in 
Plate XXIX. When pieces are sketched in this way, they are 
said to be shown in perspective; they are also termed picture 
sketches, as they are shown tipped and swung around from the 
regular squarely viewed position of the ordinary blueprint. Blue- 
prints Nos. 2, 3, and 4, Plate XXX, representing a spur gear on 
the crankshaft, a hub for a pulley, and a spur gear on the bottom 
shaft, respectively, are shown viewed squarely from the front, and 
the real difference between them and most of the blueprints which 
we have studied lies in their being made by free-hand pen methods 
rather than by the use of drawing instruments. An end view of 
blueprint No. 2, 3, or 4 would show a series of concentric circles. 
Finish / marks indicate the working surfaces which are to be finished 
by some method of machining. 



48 BLUEPRINT READING 

In Nos. 2 and 4 cwo dotted working lines and a lettered note 
tell us that a j^-inch keyway is to be machined in the surface of 
the holes through the central hubs of these gears. In the case of 
No. 2, a lettered note states that four -j^-inch holes on a 6|-inch 
circle are to be drilled through the web of the gear, and the 
sketch shows that these are placed in slightly raised hubs, or 
bosses. It will be noted by the careful reader that, while in most 
instances the finish / marks are placed in the usual manner on the 
working lines of the views, in some cases they are given with 
the dimension figures. As a case in point, take the diameter of the 
longer hub in No. 2. Here the finish / mark follows the dimension 
figures thus, 2f " /. Several similar cases will be noted in these 
sketches by the interested reader. While most machine gears 
have "cut" teeth, this is not universally so on certain lines of 
machinery and lettered notes at the top of No. 2 and No. 4 state 
that these gears have "cut" teeth. 

PLATE XXXI 

MISCELLANEOUS MECHANISMS USED ON CROMPTON- 
KNOWLES LOOMS 

Plate XXXI, like the two preceding plates, is made up of 
four blueprints originally 4|"X5|". Reading the title plate, we 
learn what each piece is and the material used. Blueprints Nos. 
1, 2, and 4 show, respectively, a stand for a shipper and lock lever, 
an angle iron post, and a guide for a lifter rod, and they are pic- 
ture, or perspective, views. No. 3 is the ordinary type of free- 
hand sketch and shows a front and an end view of a ratchet and 
pinion. While no special directions are needed in reading, atten- 
tion is called in No. 1 to the f-inch hole near the lower part of 
the piece. While this shows the stud ^^757 in place, the stud is 
evidently a separate piece. In No. 2, the long shank has no finish 
/ marks but is marked |" /. In No. 3 two views are necessary 
to show' that one set of teeth is on a slender hub. 

PLATE XXXII 

BRASS CHECK VALVE 
First=Angle Projection. While "Mechanical Drawing," Parts 
I, II, and III, does not analyze in detail the method of projection 



\^0. 108174-- 5 




'^^— OIL 



(^J Ai"TAP 




WS^-s"f 



5TUD ^4757 



J\11L STAND rOR SHIPPER e< LOCK LEVCR LOOM TIRE FABRIC 

MOTION . DRIVE MATERIAL 0.1. 

FOR DtTAlL StL DATt 4- 15- 18 



TITLE AN6LE IRON POST 
MOTION WARP STOP 
FOR DETAIL SEE 



NO. IO8I79 



LOOM P/?0/ COTTON 
MATERIAL C. /. 
DATE 4-/5- 18 



^150 T. RATCHET 



THI5 VIEW 5H0W^ 
V R.H. * 108 1 76 



ur\x 



Vl^i' 



TITLE RATCHET 6<- PINION 

MOTION 7»/rf d//' Y Y y I 

f-OR DETAIL SEE A A A I 



LOOM TAPE 
MATERIAL C. I. 
DATE 4-- 16- 18 



OPPOSITE HAND 

or 6^4-00 



^ €, 



TITLE 6UIDE FOP UFT£R ROD 
MOTION LAY 

FOR DETAIL SEE 



LOOM CROMPTON COTBLANn^ 
MATERIAL CI. 
DATE 4-17-18 



3169 D 








m 



SCALE /i w B/?A55 CH^CK 

FULL SIZE FOR LEA THFR OR A 5BE5T05 DISC 



MARCH 50 im THE PRATT 6< CADY CO. INC. 

RETRACED HARTFORD, CONN. 

10-6- 14 

MM.f9 3189 D 



BLUEPRINT READING 49 

used in Plate XXXII, readers of blueprints often have such 
placed in their hands. The blueprints of machine parts shown in 
tins text sire, with this one exception, drawn in what is known as 
third-angle projection. In addition to what this book contains on 
views and their arrangement, "Mechanical Drawing," Part III, 
defines and illustrates first-angle and third-angle projection and the 
blueprint reader should study the opening pages of Part III. In 
Fig. 97, Part III, the reader will note that the lines of the piece 
viewed are sent forward on a plane surface. In other words, 
instead of placing the object we are viewing on the far side of 
some material like plain glass and viewing it through the glass and 
then making on the glass a sketch of what we see, the object is 
placed in front of the glass and we make the sketch on the glass 
as if we sighted along its edges and drew lines on the glass in line 
with the edges we were sighting. Looking at an object in this 
manner places the right end view in the blueprint at the left side 
of the front view instead of at the right side as in previous blue- 
prints, and the surface lines seen in looking down on the top of 
the object are shown below the front view. 

Placing of Views. If this method is clear in the reader's 
mind, let him return to Plate XXXII. He will observe that the 
front view of this l|-inch brass check valve has been placed at the 
upper left-hand corner of the sheet. Just below the front view 
and centered with it is the view one would get of this valve if he 
were viewing it on its top side, or upper surface. By the regular 
third-angle system of placing views, the top view would be shown 
above the front view. The end view, as the careful reader will 
note, represents the view one would get if looking at the left end 
of the front view. "While it is, then, a view of the left end of the 
valve and would, in ordinary view arrangement, be placed at the 
left of the front view, it is by the first-angle arrangement of views 
placed at the right of the front view. In tracing the location of a 
line from one view to another, the blueprint reader will need to 
use care if he is not accustomed to this method of showing views. 

Details of Blueprint. Other than the arrangement of views, 
this blueprint is easily read, having, as it does, a hollow spherical 
body with hexagon ends and a circular hole in its upper side, 
a hexagon cap screwed into the top side hole, and an internal 



50 BLUEPRINT READING 

swing hinged valve flapper. A tapped hole in the upper right 
corner of the body is made at an angle of 40 degrees with the 
axis of the valve body and into this is screwed a special plug as 
shown. The flapper is hinged on a small diameter spindle which 
is centered and held in place by two bearing plugs placed opposite 
each other in the body of the valve. The flapper consists of a 
hinged frame, a circular disc having a ring of leather or asbestos 
in its under side groove, a bolt, a nut, and a washer to hold the 
ring in the disc groove and the ring and disc onto the hinged frame. 

PLATE XXXIII 
SPINDLE 

When interpreting Plate XXXIII, the reader will note from 
the title plate that the spindle is made from 15-point machine 
steel. Fifteen point when used in this manner means that the 
carbon content in the steel is fifteen-hundredths of one per cent. 
The shop man and the mill man shorten this by saying or writing 
it 15 point. A front view only is needed to show all the necessary 
outlines of the spindle and to give all the necessary dimensions 
for the workman as an end view would consist of a series of con- 
centric circles except for the keys and their seatings. 

Dotted lines centered with the center line of the work and 
drawn from end to end of the view show a hole through the 
length of the spindle. A lettered note tells us that in the right- 
hand, or nose, end of the spindle this hole is No. 12 taper to a 
plug depth of 6 inches. In producing the hole, the workman 
would first drill a hole 7f inches deep plus or minus | inch, using 
a Ij^-inch drill, and then he would continue the hole completely 
through the length of the spindle, using a 1-inch drill. A lettered 
note with an indicating arrowhead informs us that the rear end of 
the hole is to be chamfered | inch for center. Another lettered 
note" states that the spindle bearings are to be pack hardened at 
least Ys inch deep. A lettered note placed near the nose of the 
spindle tells us that the 3|-inch and the 3|-inch diameters are to 
be a forced fit in part #4470. Some makers of working blue- 
prints use the term press fit instead of force fit. Either term 
would indicate that part #4470 is to be pressed onto the spin- 
dle at the places indicated by the arrow points. The lettered 



1 lb p. 

^-CHAMFER g" roil aNT^R ^\, 

WRINGING FIT IN PT #5007 
5PANNFR NUT PT # 4484 



5PANNFR NUTS 
PT. # 44-67 



PACn HARDEN AT LFA5T // DEEP ' 

WHEN TURNIN6 LEAVE NO nUET UNU55 CALLED FOI?. 
WHEN 0PINDIN6 LEAVE FILLET MADE BY WHEEL NOT TO 
EXCEED // PAWU5 iyNLE55 OTHERWISE CALLED FOR. 



FORCE FIT IN 
PT #4470 



DO NOT THREAD UNTIL AFTER 
HARDEN IN6 6C ORINDINO 
ON DIAMETERS 



WMmUl blttl 

rXALE 

FULL S17F 



XXXIII 



Unkii Otherwbe Specified. Limih On Tf>i3 Dromng A, 
yimeniiom Of Anqln ± I" Reamed And Boreri tInlPi jfd 



DRAWN SY 6M.D./J ^^^^ 3P1NDLE 
CtitCKED BY A.O.B./B. j . , .^. 

APPROVED BY ^^«;.^^ '"'^ '^^^ '^ ^.C7./J. 

DAT £ 4-9-18 

"NORTON GRINDING CO., WORCESTER MA55.,U5A 







IB-ANCHORS T^ll- ™?X- TR.iXr W.4l-TP7X.-TP.8X-irTK9.XAKMLALmE hWANTtO |2 «'/s 

W/lWrfO TR.5X-LIKiJRM.EXaPTNOUl>-IWANJ[Dm5X OF EACH. 

lR.(,X:mtlR.lXtXCEPJN0nD-l-WANTeDW.6X ■ C; -. _ 



^f^^^^^^-:^^ -^'^.. 






3 7R.I.ZI-WANTED. >15 iTOtV/V /lOT WOTffl TR.'iZ. 







"^^^ 



7R.7.Z- hWANJCD m 



TR4Z-I WANTED AS 5H0WN JRA.I- PARI NOT SHOWN 
, .^ - --.^ SAMEA5 TR.I.Z. 



IRBllWANTfa TR.e.Z-PART 
NOT SHOm SAM A3 TR. 7Z. 




BCII-ZL^ii>^?i' _^ 






iSr'iui^'^j,. 



'-'shown 5AMC AS TRI.2. 






bCS-ZL^Z'/mZ' 

x%x//'S!'a'76. 



, , , I S^U7-Ze Zi'Z^xJ'' 

[jP '5'''/*"i, S'/02" ^ <^''} Z'4'iLO 

TR-Wu^ x/ w \/ 1 N / '" Tl?''^'z- 1 WANTED TR92PART 

CH Price X A A I V NOT SHOWN SAME A5 TR 7Z 



, ^r.^,.'...V^ TM-._^,^,„^ Wifj|" ^/VAf55 NOTED 

■loAzlz'.z', ^TD. QA6ES UNLESS NOTED 

r ivvw-:rio*- paint:- I- COAT BLACK 



IR <b7r I- WANTED TR-6.Z- PART NOT SHOWN 
SAME Ae TR.IZ. 



J. 1214. SH 



' BLUEPRINT READING 51 

note placed at the left end of the spindle refers to a wringing fit. 
A wringing fit is one in which the parts are so fitted in dimensions 
as to have to be wrung, or twisted, together; some workmen inter- 
pret this to mean a fitting so snug that the pieces go together by 
lightly rapping them. In any case, it means a fit so snug that a 
little forcing is needed to slip the pieces together. The reader's 
attention is called to the limiting tolerances as expressed by the 
plus and minus signs and to the printed directions placed at the 
lower edge of the sheet which state that "unless otherwise speci- 
fied, limits on this drawing are ±0.005"; dimensions of angles ±1°; 
and reamed or bored holes standard to 0.001" small". The term 
Woodruff key refers to the Whitney system of using Woodruff keys. 

PLATE XXXIV 
\ ROOF TRUSS 

Plates XXXrV and XXXV are shown for the reason that the 
average shop man may be at times called upon to use such. 
Plate XXXIV shows a piece of structural work known as a roof 
truss. The word "truss" is shortened to Tr. on the blueprint. 
Steel structural work such as trusses, beams, girders, and columns 
is usually made up of angles, I beams, channels, plates, etc., 
riveted in such a manner as to get the desired construction. The 
various angles, channels, etc., are known as shapes and are hot 
rolled at the steel mills, straightened, and sold in open market. 

The truss shown in Plate XXXIV is built up of angles of 
varying lengths riveted together and to flat pieces of plate known 
as gussets, or sometimes gusset plates. The several pieces of 
angles are given a letter symbol. In the roof truss shown the 
short pieces of angle steel used to tie the upper and lower parts 
together are symbohzed by D and show on the blueprint as D-1, 
D-2, etc. The gusset plates are symbolized by G and appear on 
the blueprint as G-1, G-2, etc. In many cases a truss is too 
long to ship complete and has to be partly completed at the place 
used, or, as it is termed, in the field, and rivets driven after the 
truss leaves the shop are known as field rivets. The rivets which 
are to be driven while the truss is being built in the shop are 
indicated in the blueprint by small full circles, while the position 
of field rivets is shown on the angles by small white circular spots. 



52 



BLUEPRINT READING 




Fig. 2. 



SHORT LSa' \^ 
Details of Angle Sections 



Noting what has been said relative to riveting, it will be observed 
that the blueprint shows that this truss is to be shipped in three 
sections and field riveted at the place where it is to be used. 

A steel angle as rolled has the form shown in Fig. 2. The 
upright and the horizontal parts are known as the legs of the 

angle. In the truss shown, 
two of these angles about 30 
feet 10 inches long are placed 
back to back to form the left 
half of the upper slant of the 
truss. In the same manner, 
two angles about 29 feet 11 j^ 
inches long are placed back to 
back to form the right upper half of the truss. Previous to riveting 
the angles together for making each top slant, gusset plates as shown 
at G-lf G-2, G-4-, G-5, and G-7 are slipped between the angles and 
the whole is riveted together. In a like manner, the lower chord of 
the truss is riveted up. It will be noted that the gusset plates G are 
trimmed to come flush at the outer surfaces of the truss, but that 
they project into the inside of the truss a distance sufficient to 
allow the several short angles to be riveted to them. It will also be 
observed that when the angles are riveted together back to back 
with gusset plates, the surfaces of the legs of the angles are sepa- 
rated by an amount equal to the thickness of the gusset G. Any 
rivets driven through the angle plates at space points held apart by 
the gussets have small washers slipped into the crack, or space, 
between the angles, and the rivets are then set up through the 
washer. This is shown on the blueprint by means of a dotted 
circle around the space rivets. It must be noted that the bottom 
chord of the truss is not made up of single-length angles but is 
spliced at points about 15 feet 4| inches from each end of the truss. 
Where a splice such as this occurs in the bottom chord of a truss, 
it is strengthened by riveting a splice plate onto the bottom of the 
angles, covering and tying the splice. 

Instead of giving in degrees and minutes the angle one piece 
makes with another, as is done in machine shop drawings, &, 
small triangle is placed on the piece, as shown at the upper end 
of angle D-S and on its lower side. This means that the line 



I 



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II -PLAN OF- 

FOUNDRY BUILDING 

WORCESTER POLYTECHNIC INSTITUTE 
Plans bg C.E Dept. ^ -INCH = I ■ FOOT June 1902 



BLUEPRINT READING 53 

on the gusset plate along which the rivet holes are to be placed 
rises from a base line 8xi inches in 12 inches. The layout man 
accordingly measures off a base line on the gusset 12 inches in 
length and erects a perpendicular line on one end 8x1 inches in 
height. From this height he may scribe a line to the other end of 
the 12-inch base line and this is the gage line for the rivet holes. 
In all structural steel work the rivet holes are spaced along lines 
located a given distance from the back of the angle. These lines 
are termed gage lines and are not center lines in the usual sense. 
For example, in the view shown the reader will note that in the 
top member of the truss in the front view there are two gage 
lines and therefore two lines of rivets. 

It will be observed that, while the top view of the truss is 
placed above the front view as in previous blueprints which we 
have studied, it parallels the slant of the truss. If a bottom view 
were given of this truss, it would show as if viewed from inside 
the truss; such a view is distinctly different from the bottom 
views already studied, and this point should be carefully noted in 
reading structural drawings. 

PLATE XXXV 

PLAN OF FOUNDRY BUILDING 
Plate XXXV shows the plan of a foundry building. While 
the blueprint is more than ordinarily complete, it fairly represents 
such plans. The walls of the building are of brick and the win- 
dows are the prominent features of the walls. The reader should 
observe that the outside dimensions of the building, the door 
sizes, and the thickness of the walls are given; the columns, posts, 
interior walls, and partitions are located; the center-to-center dis- 
tances are given; the foundry equipment is given and its position 
located on the plan; all stairways are indicated; and room measure- 
ments are given. Attention is called to the method of represent- 
ing the windows by means of two parallel lines placed across the 
openings in the brick wall and to the method of showing the doors 
swung partly open. The plan shows a gallery floor along one side 
of the building. On this floor are located the office of the fore- 
man, the charging floor for the cupolas, the motor room, etc.; the 
gallery floor is supported partly by the 9-inch latticed channel 



54 BLUEPRINT READING 

columns and partly by a series of 6-inch round cast-iron columns. 
Three sets of doors are shown opening into the air and one open- 
ing into a tunnel to the shop. As a means of carrying off roof 
water and drainage from the pickling bed and cleaning room, a 
soil pipe line is shown. As most of this line of pipe is placed 
beneath the floor, it appears in the blueprint as a double dotted 
line. Two tile-lined chimneys are shown; one of these is for the 
brass furnace and one for the core oven. The core room is partly 
inclosed by means of a low wall capped with cast plates. The 
8-foot door opens onto a driveway as do the two 5-foot 8-inch 
doors. These driveways and the street along the front of the 
building are not shown in the plan, but the street location could 
be assumed by the fact that the soil pipes, the clay drain, and the 
water pipes extend beyond the wall in a certain direction. 

PLATE XXXVI 

TYPICAL FIRE INSURANCE MAP 

In fire insurance work the graphic description of a property 
has an important function; the custom is to show a plan or simple 
diagram of the insured properties, Plate XXXVI, adding certain 
simple devices for indicating such features of the building as may 
conveniently be described in this manner. 

The map of a fire insurance risk gives the general location 
of the risk and its position relative to other risks. It also shows a 
scale drawing of the ground plan of the building, giving the dimen- 
sions, area, and, at the same time, a perfect idea of its general 
contour and the relation of the subdivisions of the building. By 
varying the thickness of the wall lines they are made to represent 
different kinds of walls. Unfinished or incomplete walls are repre- 
sented by dotted lines; open spaces in the line indicate where the 
wall is interrupted or where a window opening occurs. Color is 
used to a large extent to indicate the different forms of construction ; 
certain symbols, which follow in a measure the shapes of the things 
they represent, are used to shorten the description; and of course 
the use of initial letters is too well known to be more tlian mentioned. 
These symbols, it must be understood, are purely arbitrary but, 
having become established and recognized, they form the symbol 
language of the inspector and must be studied in a practical way in 












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BLUEPRINT READING 55 

order to be recognized when presented. A few of these symbols and 
their description are given to convey some idea of the manner in 
which the*map may be interpreted. 

A soHd thick Hne -«— ™— — — represents an independent wall. 
A soHd thin line represents a party wall. A distinct break in the 

line representing a division or side wall indicates 

an opening made by a doorway or arch. A small curved line 

--T— — *— or a short line at right angles indicates the presence 

of a fire door^ the auxiliary line being placed on the side of the wall 
the door is on. An auxiliary line on each side indicates a fire door 

on each side of the walls. A double curved line 




is used to represent a standard fire door. 

black dot on the inside end of a window line indicates a window 
opening on that side of two adjoining walls. If the black dot is 
missing, it means that there is no window on this floor. A single 
curve over the end of the window line represents a non-standard fire 
shutter. A straight line indicates the presence of wire glass. The 
initial H within a hollow square is used to represent a hoistway 



or hatch. | S [ 1 1 1 | [ | | [ The letter S within a hollow square is 

used to represent a stairway. A stairway is also represented by a 
rectangular outline crossed by straight lines supposed to represent 
the stair steps. A solid black oblong figure represents a horizontal 
boiler, while a solid black circle represents a vertical boiler. A thin 



line around the solid black oblong figure [BK^B^ and the margin 

colored in red represents a horizontal steam boiler which is bricked 
in. A small thin-lined circle with diagonals and a black dot at 

their intersection (SC)^'5. indicates an automatic sprinkler riser. 

A sprinkler pressure tank is represented thus d D . 

Plate XXXVI is a copy of a map issued in connection with the 
adoption of these symbols by the Fire Underwriters Uniformity 
Association and brings into use practically all the symbols needed 
in maps of this character. While this type of blueprint is special, 
the ability to read it is of value. 



56 BLUEPRINT READING 

PLATES XXXVII TO XLI 

TYPICAL PLANS OF A TWO=STORY RESIDENCE* 

The average person looking at a building has little conception of 
the many drawings it takes to fully illustrate the structure on paper. 
Many trades are concerned in the rearing of the building. Each one 
of them must be told in the drawings what portion of the work they 
have to execute, and their work must be clearly and fully illus- 
trated so that it will fit in with all the other work without friction 
or confusion. To bring about this result, it is of the utmost 
importance that the drawings be as complete as they can be made 
— nothing left to chance or guesswork and all sides of the problem 
represented. Take, for instance, a staircase; one reason for diffi- 
culties occuring time and again in constructing this important part 
of a building is the fact that the stairs have been shown only from 
one view. If it had been drawn out from different angles showing 
the various sections besides the elevations, then any mistakes like 
lack of headroom would have been discovered while making the 
drawings and not during the process of building. The writer 
speaks from experience in this matter. 

Five of the principal drawings of a set of plans for a two- 
story residence have been selected to give a good idea of the 
methods employed to illustrate to the builder what he is to do. 

A word must be said here on the importance of the lettering of 
a drawling. Anyone familiar with drawings knows that some draw- 
ings are more easily read than others. A first glance at a drawing 
should tell the subject illustrated. Next in importance on a plan 
would be the designation of the rooms. In still smaller type would 
be shown all the descriptive matter. The disposition of the dimen- 
sion figures must be such as not to confuse the eye and they must 
not interfere with the descriptive matter. The main dimensions 
should stand out clearly. Bearing these points in mind will assist 
considerably in one's intelligent reading of a drawing. 

First=Floor Plan. Plate XXXVH shows the first-floor plan 
of the residence. At the right of the drawing is a diagram called 
"key to materials." This shows the method used to indicate the 
various building materials. This "key" applies to all the drawings. 

* Prepared by H. V. Von Hoist, Architect, Chicago. 




r/Rsr Floop Plan 



XXXVII 



BLUEPRINT READING 57 

There is no recognized standard for indicating materials in a 
certain way; each architect's office has its own individual method 
of indication. On the plan it will be seen that the brick walls 
stand out very clearly due to the indication, thus enabling one to 
read the general arrangement of the house without difficulty. The 
interior frame and plastered partitions are shown merely by two 
lines. Note the difference in showing a double-hung window from 
a swinging window. The double-hung window has a box frame 
which is recessed into the wall. The distance that this frame sets 
back from the outside wall line is called the reveal. In this house 
all the reveals are 8 inches. This is one distinguishing feature 
between a solid-brick house and a brick-veneer house. In the 
latter the reveal cannot be more than 4 inches. Swinging windows 
are shown on either side of the fireplace in the living room. Here 
there is no recess in the wall, as a plank frame is used instead of 
a box frame. These windows are double-swinging, or casement, 
windows swinging into the room, as shown by the slanting lines. 
Doors are shown by describing an arc of a circle with the center 
at the point where the door is hinged and drawing a line from the 
center to the edge of the arc. Where there is an opening without 
doors between rooms and the top of the opening is brought down 
below the ceiling line, it is called a cased opening and dotted lines 
indicate this fact. Lights, radiators, and dimension lines are shown 
in watered-ink lines in order that they may print lighter and may 
not confuse the drawing by showing too many lines of the same 
weight. Ceiling lights and wall brackets are shown by a circle; 
the wall bracket has a line tying it to the wall. Floor and base 
outlets are shown by a small rectangle. If more than one light is 
to be on a fixture, the fact is marked in the circle or rectangle. 
Switches are indicated by the letter S and a dotted line running 
to the light which it controls. Where a switch is marked S-S it 
denotes a three-way switch. The radiators are drawn to the 
proper size and the number of square feet of radiation is marked 
in the rectangle. The method used in dimensioning the plan is 
easily followed. Windows are figured between finished brick jambs; 
in a frame building the size of the glass only is given. The inside 
partitions are figured to the center of the partition. The ordinary 
plastered stud partition is slightly less than 6 inches but for con- 



58 BLUEPRINT READING 

venience sake it is figured at 6 inches. If no dimension is given, 
it is a 6-inch partition. Where the partition has to be made 
wider to accommodate soil pipes it ought to be shown or figured. 
The same appHes if the partition is less than 6 inches as in the 
case where the studs are set sideways, making only a 4-inch par- 
tition. It does not make as stiff a wall but sometimes is desirable 
on account of saving space. In this plan the walls are figured 
1 foot 3 inches thick, which is the distance from the outside of 
the brick wall to the inside of the plaster wall. This allows 1-inch 
furring strips on top of the 13-inch brick wall. 

The plan shows lines marked B-B, C-C, D-D with a light 
dash and dot. These indicate the vertical sections through the 
building that are shown on separate drawings, the direction of the 
arrows showing which way the observer is looking; for instance, 
section C-C is taken through the dining porch, dining room, stair 
hall, vestibule, and front porch, looking toward the south. 

Second=Story Plan. Plate XXXVIII shows the second-story 
plan, the roofs over the one-story portions being shown. 

Attention is called to a feature in this plan where the ser- 
vants' bedrooms and bathroom are on the second floor instead of 
in a hot attic, which is the usual way in this type of house. The 
attic has been omitted entirely, there being only a scuttle in the 
hall by means of which the space under the roof can be reached. 

North Elevation. Plate XXXIX shows the north elevation. 
The portions of the building below the finished grade are indicated 
in dotted lines. The stairs too are brick joints drawn in with 
light lines. All dimensions are figured from the sidewalk grade 
and the basement floor. Window-glass sizes give as first dimen- 
sion the width and then the height, i.e., 26/20 means glass 26 
inches wide and 20 inches high. The floor lines given are the 
finished floors unless otherwise noted. Window heights are figured 
from 'top of slope sill to bottom of window head. 

Exterior and Interior Details. Plate XL shows the exterior 
and interior details of the residence. Portions of the building are 
drawn on a larger scale to explain more fully what is required. 
Thus on the left-hand side of the sheet is a corner of the front of the 
building showing half of the entrance arch. At the second-story 
window is interposed a plan through the corner at the second- 



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BLUEPRINT READING 59 

story window level. Alongside of this elevation is a section taken 
through the center of the entrance arch and the wall above. It 
shows the side archways in elevation beyond the dash-and-dot 
line. Next is a detail of a portion of the front bay window with 
a plan through the window jamb interposed. Alongside of this 
exterior is a view of the interior of the bay window showing the 
base, window trim, and cornice. Finally comes the vertical section 
through the bay window, thus giving a complete picture of this 
feature of the house. Above the bay-window drawing is a detail 
of half a window showing the trim in the servants' rooms, and to 
the right of this a detail of the cornice around the sleeping porch. 
The student should follow these details on the floor plans in order 
to clearly understand what portions of the building are being shown 
in these details. Details must be shown in parts as it would take 
too much time and paper to draw a feature completely when half 
of the feature or less will explain how it is to be built. 

First=Floor Framing Plan. Plate XLI shows the first-floor 
framing plan. Separate framing plans are not always made for 
a building of this size, but where steel is used for the main sup- 
ports it is a great help and causes less confusion on the general 
plans to have the separate framing drawings. The walls and 
openings and all wood beams are shown by light lines. All steel 
work is shown in heavy lines. Each wooden joist is indicated by 
a line. The width and depth of the joist are given, and distance 
that they are spaced on centers. Where there are three lines close 
together, they are marked 3, then the width of joist and depth. 
The steel lintels over the windows are marked with a number and 
the size given in the upper left-hand corner. 

In conclusion let it be said that it takes patience, and a great 
deal of it, to draw a set of plans for any building and make it so that 
all the ins and outs of the building can be worked out in concrete 
form, and so also it takes patience to read a house plan and follow 
it through in all its details and not viiss some important items. 

Plans are often incomplete and inaccurate or faulty and the 
reader of a plan must train himself to become so adept in reading 
a plan that he can not only picture for himself the building as it 
is intended, but can get a complete picture even though some 
of the details may possibly be wTongly shown, or not shown at all. 



BLUEPRINT READING 



Read Carefully: Place your name and full address at the head of the 
paper. Any cheap, Hght paper Uke the sample previously sent you may be 
used. Do not crowd your work, but arrange it neatly and legibly. Do not 
copy the answers from the Instruction Paper; use your own words, so that we 
may be sure yo^i understand the subject. 



1. What is a blueprint? 

2. Describe the process of making a blueprint. 

3. What should a workman understand in order to read a 
blueprint correctly? 

4. How would you arrange to show a view of large work on 
a small sheet of paper? 

5. State the meaning of the following sjnnbols: L.H., C.I., 
O.H.S. and F.A.O. 

6. Give the symbols for the following: Finished Surface, 
Diameter, Pipe Tap and Tool Steel. 

7. Sketch a conventional screw-thread as it is generally 
shown on a blueprint. 

8. Show by sketch, with dimensions, an outline of the teeth, 
or threads, on a worm and bobbing cutter. 

9. In tracing the location of parts, holes, etc., in what 
general position will they be in the top or end view as compared 
to their position in the front view? 

10. Read from Plate XIX just which surfaces are to be 
machined. 

11. What is tolerance, and how is it shown on a blueprint? 

12. In the armature punching, Plate XXIII — 2, what is the 
outside diameter, and how many slots _are.there?; 

13. From what kind of drawings"^ are' the blueprints in Plate 
XXIX made, and what is the advantage of these small prints? 

14. Explain third-angle projection, illustrating by sketch. 



BLUEPRINT READING 

15. Does Plate XXXII represent third-angle or first-angle 
projection? 

16. Read the greatest diameter and total length of the 
spindle shown in Plate XXXIII, and state what kind of keys are 
used. 

17. What are gage lines, as used in roof-truss blueprints? 

18. Read the outside dimensions and thickness of walls of 
the foundry building shown in Plate XXXV. 

19. What is the general purpose of such a blueprint as 
Plate XXXVI? 

20. Represent by sketches a horizontal boiler, a vertical 
boiler, and a stairway. 

After completing the work, add and sign the following statement: 

I hereby certify that the above work is entirely my own. 

(Signed) 



^lN 589^^ 



LIBRARY OF CONGRESS 



019 934 626 A 



